diff --git a/wp-includes/functions.wp-styles.php b/wp-includes/functions.wp-styles.php
index d82bb55925..823d88ce7a 100644
--- a/wp-includes/functions.wp-styles.php
+++ b/wp-includes/functions.wp-styles.php
@@ -225,14 +225,18 @@ function wp_style_is( $handle, $list = 'enqueued' ) {
  * 'suffix'      string      Optional suffix, used in combination with RTL.
  * 'alt'         bool        For rel="alternate stylesheet".
  * 'title'       string      For preferred/alternate stylesheets.
+ * 'path'        string      The absolute path to a stylesheet. Stylesheet will
+ *                           load inline when 'path'' is set.
  *
  * @see WP_Dependencies::add_data()
  *
  * @since 3.6.0
+ * @since 5.8.0 Added 'path' as an official value for $key.
+ *              See {@see wp_maybe_inline_styles()}.
  *
  * @param string $handle Name of the stylesheet.
  * @param string $key    Name of data point for which we're storing a value.
- *                       Accepts 'conditional', 'rtl' and 'suffix', 'alt' and 'title'.
+ *                       Accepts 'conditional', 'rtl' and 'suffix', 'alt', 'title' and 'path'.
  * @param mixed  $value  String containing the CSS data to be added.
  * @return bool True on success, false on failure.
  */
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 4c99bfb9d0..7948b0d819 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.9-alpha-52215';
+$wp_version = '5.9-alpha-52216';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.