diff --git a/src/wp-includes/theme.php b/src/wp-includes/theme.php
index 0526fe8f65..74c5ccda78 100644
--- a/src/wp-includes/theme.php
+++ b/src/wp-includes/theme.php
@@ -1524,7 +1524,9 @@ function get_editor_stylesheets() {
  *
  * @global array $_wp_theme_features
  *
- * @param string $feature The feature being added.
+ * @param string $feature The feature being added. Likely core values include 'post-formats',
+ *                        'post-thumbnails', 'html5', 'custom-logo', 'custom-header-uploads',
+ *                        'custom-header', 'custom-background', 'title-tag', etc.
  * @return void|bool False on failure, void otherwise.
  */
 function add_theme_support( $feature ) {