diff --git a/wp-admin/menu-header.php b/wp-admin/menu-header.php
index 6b775f4c08..a32f3a514d 100644
--- a/wp-admin/menu-header.php
+++ b/wp-admin/menu-header.php
@@ -19,7 +19,17 @@ $self = preg_replace('|^.*/plugins/|i', '', $self);
 $self = preg_replace('|^.*/mu-plugins/|i', '', $self);
 
 global $menu, $submenu, $parent_file; //For when admin-header is included from within a function.
-$parent_file = apply_filters("parent_file", $parent_file); // For plugins to move submenu tabs around.
+
+/**
+ * Filter the parent file of an admin menu sub-menu item.
+ *
+ * Allows plugins to move sub-menu items around.
+ *
+ * @since MU
+ *
+ * @param string $parent_file The parent file.
+ */
+$parent_file = apply_filters( 'parent_file', $parent_file );
 
 get_admin_page_parent();
 
@@ -195,6 +205,11 @@ function _wp_menu_output( $menu, $submenu, $submenu_as_parent = true ) {
 <?php
 
 _wp_menu_output( $menu, $submenu );
+/**
+ * Fires after the admin menu has been output.
+ *
+ * @since 2.5.0
+ */
 do_action( 'adminmenu' );
 
 ?>