diff -r 7b1b88e27a20 -r 48c4eec2b7e6 wp/wp-includes/class-wp-block-styles-registry.php
--- a/wp/wp-includes/class-wp-block-styles-registry.php	Thu Sep 29 08:06:27 2022 +0200
+++ b/wp/wp-includes/class-wp-block-styles-registry.php	Fri Sep 05 18:40:08 2025 +0200
@@ -12,6 +12,7 @@
  *
  * @since 5.3.0
  */
+#[AllowDynamicProperties]
 final class WP_Block_Styles_Registry {
 	/**
 	 * Registered block styles, as `$block_name => $block_style_name => $block_style_properties` multidimensional arrays.
@@ -34,21 +35,39 @@
 	/**
 	 * Registers a block style for the given block type.
 	 *
+	 * If the block styles are present in a standalone stylesheet, register it and pass
+	 * its handle as the `style_handle` argument. If the block styles should be inline,
+	 * use the `inline_style` argument. Usually, one of them would be used to pass CSS
+	 * styles. However, you could also skip them and provide CSS styles in any stylesheet
+	 * or with an inline tag.
+	 *
 	 * @since 5.3.0
+	 * @since 6.6.0 Added ability to register style across multiple block types along with theme.json-like style data.
+	 *
+	 * @link https://developer.wordpress.org/block-editor/reference-guides/block-api/block-styles/
 	 *
-	 * @param string $block_name       Block type name including namespace.
-	 * @param array  $style_properties Array containing the properties of the style name, label,
-	 *                                 is_default, style_handle (name of the stylesheet to be enqueued),
-	 *                                 inline_style (string containing the CSS to be added).
+	 * @param string|string[] $block_name       Block type name including namespace or array of namespaced block type names.
+	 * @param array           $style_properties {
+	 *     Array containing the properties of the style.
+	 *
+	 *     @type string $name         The identifier of the style used to compute a CSS class.
+	 *     @type string $label        A human-readable label for the style.
+	 *     @type string $inline_style Inline CSS code that registers the CSS class required
+	 *                                for the style.
+	 *     @type string $style_handle The handle to an already registered style that should be
+	 *                                enqueued in places where block styles are needed.
+	 *     @type bool   $is_default   Whether this is the default style for the block type.
+	 *     @type array  $style_data   Theme.json-like object to generate CSS from.
+	 * }
 	 * @return bool True if the block style was registered with success and false otherwise.
 	 */
 	public function register( $block_name, $style_properties ) {
 
-		if ( ! isset( $block_name ) || ! is_string( $block_name ) ) {
+		if ( ! is_string( $block_name ) && ! is_array( $block_name ) ) {
 			_doing_it_wrong(
 				__METHOD__,
-				__( 'Block name must be a string.' ),
-				'5.3.0'
+				__( 'Block name must be a string or array.' ),
+				'6.6.0'
 			);
 			return false;
 		}
@@ -72,11 +91,14 @@
 		}
 
 		$block_style_name = $style_properties['name'];
+		$block_names      = is_string( $block_name ) ? array( $block_name ) : $block_name;
 
-		if ( ! isset( $this->registered_block_styles[ $block_name ] ) ) {
-			$this->registered_block_styles[ $block_name ] = array();
+		foreach ( $block_names as $name ) {
+			if ( ! isset( $this->registered_block_styles[ $name ] ) ) {
+				$this->registered_block_styles[ $name ] = array();
+			}
+			$this->registered_block_styles[ $name ][ $block_style_name ] = $style_properties;
 		}
-		$this->registered_block_styles[ $block_name ][ $block_style_name ] = $style_properties;
 
 		return true;
 	}