Add @SInCE notes.

src/wp-includes/style-engine.php

@@ -113,6 +113,7 @@ function wp_style_engine_get_styles( $block_styles, $options = array() ) {
  *     .elephant-are-cool{color:gray;width:3em}
  *
  * @since 6.1.0
+ * @since 6.6.0 Added support for `$rules_group` in the `$css_rules` array.
  *
  * @param array $css_rules {
  *     Required. A collection of CSS rules.

src/wp-includes/style-engine/class-wp-style-engine-css-rule.php

@@ -39,6 +39,7 @@ class WP_Style_Engine_CSS_Rule {
 	 * A parent CSS selector in the case of nested CSS, or a CSS nested @rule,
 	 * such as `@media (min-width: 80rem)` or `@layer module`.
 	 *
+	 * @since 6.6.0
 	 * @var string
 	 */
 	protected $rules_group;
@@ -47,6 +48,7 @@ class WP_Style_Engine_CSS_Rule {
 	 * Constructor.
 	 *
 	 * @since 6.1.0
+	 * @since 6.6.0 Added the `$rules_group` parameter.
 	 *
 	 * @param string                                    $selector     Optional. The CSS selector. Default empty string.
 	 * @param string[]|WP_Style_Engine_CSS_Declarations $declarations Optional. An associative array of CSS definitions,
@@ -103,6 +105,8 @@ public function add_declarations( $declarations ) {
 	/**
 	 * Sets the rules group.
 	 *
+	 * @since 6.6.0
+	 *
 	 * @param string $rules_group A parent CSS selector in the case of nested CSS, or a CSS nested @rule,
 	 *                            such as `@media (min-width: 80rem)` or `@layer module`.
 	 *
@@ -116,6 +120,8 @@ public function set_rules_group( $rules_group ) {
 	/**
 	 * Gets the rules group.
 	 *
+	 * @since 6.6.0
+	 *
 	 * @return string
 	 */
 	public function get_rules_group() {
@@ -148,6 +154,7 @@ public function get_selector() {
 	 * Gets the CSS.
 	 *
 	 * @since 6.1.0
+	 * @since 6.6.0 Added support for nested CSS with rules groups.
 	 *
 	 * @param bool $should_prettify Optional. Whether to add spacing, new lines and indents.
 	 *                              Default false.

src/wp-includes/style-engine/class-wp-style-engine-css-rules-store.php

@@ -121,6 +121,7 @@ public function get_all_rules() {
 	 * If the rule does not exist, it will be created.
 	 *
 	 * @since 6.1.0
+	 * @since 6.6.0 Added the $rules_group parameter.
 	 *
 	 * @param string $selector The CSS selector.
 	 * @param string $rules_group A parent CSS selector in the case of nested CSS, or a CSS nested @rule,

src/wp-includes/style-engine/class-wp-style-engine-processor.php

@@ -58,6 +58,7 @@ public function add_store( $store ) {
 	 * Adds rules to be processed.
 	 *
 	 * @since 6.1.0
+	 * @since 6.6.0 Added support for rules_group.
 	 *
 	 * @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

src/wp-includes/style-engine/class-wp-style-engine.php

@@ -364,6 +364,7 @@ protected static function is_valid_style_value( $style_value ) {
 	 * Stores a CSS rule using the provided CSS selector and CSS declarations.
 	 *
 	 * @since 6.1.0
+	 * @since 6.6.0 Added the `$rules_group` parameter.
 	 *
 	 * @param string   $store_name       A valid store key.
 	 * @param string   $css_selector     When a selector is passed, the function will return