diff --git a/src/wp-includes/block-supports/block-style-variations.php b/src/wp-includes/block-supports/block-style-variations.php
index 8312f5edcfa6a..a44ecdd396e18 100644
--- a/src/wp-includes/block-supports/block-style-variations.php
+++ b/src/wp-includes/block-supports/block-style-variations.php
@@ -249,7 +249,7 @@ function wp_resolve_block_style_variations( $variations ) {
 		 * Block style variations read in via standalone theme.json partials
 		 * need to have their name set to the kebab case version of their title.
 		 */
-		$variation_name  = $have_named_variations ? $key : _wp_to_kebab_case( $variation['title'] );
+		$variation_name = $have_named_variations ? $key : _wp_to_kebab_case( $variation['title'] );
 
 		foreach ( $supported_blocks as $block_type ) {
 			// Add block style variation data under current block type.
@@ -409,6 +409,7 @@ function wp_enqueue_block_style_variation_styles() {
  * Registers any block style variations contained within the provided
  * theme.json data.
  *
+ * @since 6.6.0
  * @access private
  *
  * @param array $variations Shared block style variations.
@@ -468,6 +469,7 @@ function wp_register_block_style_variations_from_theme_json_data( $variations )
  * - the theme's partials (standalone files in `/styles` that only define block style variations)
  * - the user's theme.json (for example, theme style variations the user selected)
  *
+ * @since 6.6.0
  * @access private
  */
 function wp_register_block_style_variations_from_theme() {
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-global-styles-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-global-styles-controller.php
index 24c8123b2a5a7..8ce522c1490e2 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-global-styles-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-global-styles-controller.php
@@ -231,6 +231,7 @@ public function update_item_permissions_check( $request ) {
 	 *
 	 * @since 5.9.0
 	 * @since 6.2.0 Added validation of styles.css property.
+	 * @since 6.6.0 Added registration of newly created style variations provided by the user.
 	 *
 	 * @param WP_REST_Request $request Request object.
 	 * @return stdClass|WP_Error Prepared item on success. WP_Error on when the custom CSS is not valid.
@@ -264,14 +265,16 @@ protected function prepare_item_for_database( $request ) {
 				$config['styles'] = $existing_config['styles'];
 			}
 
-			// If the incoming request is going to create a new variation
-			// that is not yet registered, we register it here.
-			// This is because the variations are registered on init,
-			// but we want this endpoint to return the new variation immediately:
-			// if we don't register it, it'll be stripped out of the response
-			// just in this request (subsequent ones will be ok).
-			// Take the variations defined in styles.blocks.variations from the incoming request
-			// that are not part of the $exsting_config.
+			/*
+			 * If the incoming request is going to create a new variation
+			 * that is not yet registered, we register it here.
+			 * This is because the variations are registered on init,
+			 * but we want this endpoint to return the new variation immediately:
+			 * if we don't register it, it'll be stripped out of the response
+			 * just in this request (subsequent ones will be ok).
+			 * Take the variations defined in styles.blocks.variations from the incoming request
+			 * that are not part of the $exsting_config.
+			 */
 			if ( isset( $request['styles']['blocks']['variations'] ) ) {
 				$existing_variations = isset( $existing_config['styles']['blocks']['variations'] ) ? $existing_config['styles']['blocks']['variations'] : array();
 				$new_variations      = array_diff_key( $request['styles']['blocks']['variations'], $existing_variations );