diff --git a/src/wp-includes/nav-menu-template.php b/src/wp-includes/nav-menu-template.php
index 5feac802f8..a0499fb9ea 100644
--- a/src/wp-includes/nav-menu-template.php
+++ b/src/wp-includes/nav-menu-template.php
@@ -195,6 +195,8 @@ class Walker_Nav_Menu extends Walker {
  *
  * @since 3.0.0
  *
+ * @staticvar array $menu_id_slugs
+ *
  * @param array $args {
  *     Optional. Array of nav menu arguments.
  *
@@ -219,7 +221,7 @@ class Walker_Nav_Menu extends Walker {
  *     @type string        $items_wrap      How the list items should be wrapped. Default is a ul with an id and class.
  *                                          Uses printf() format with numbered placeholders.
  * }
- * @return mixed Menu output if $echo is false, false if there are no items or no menu was found.
+ * @return object|false|void Menu output if $echo is false, false if there are no items or no menu was found.
  */
 function wp_nav_menu( $args = array() ) {
 	static $menu_id_slugs = array();
@@ -430,6 +432,9 @@ function wp_nav_menu( $args = array() ) {
  * @access private
  * @since 3.0.0
  *
+ * @global WP_Query   $wp_query
+ * @global WP_Rewrite $wp_rewrite
+ *
  * @param array $menu_items The current menu item objects to which to add the class property information.
  */
 function _wp_menu_item_classes_by_context( &$menu_items ) {
@@ -651,13 +656,17 @@ function _wp_menu_item_classes_by_context( &$menu_items ) {
  *
  * @uses Walker_Nav_Menu to create HTML list content.
  * @since 3.0.0
- * @see Walker::walk() for parameters and return description.
+ *
+ * @param array  $items
+ * @param int    $depth
+ * @param object $r
+ * @return string
  */
 function walk_nav_menu_tree( $items, $depth, $r ) {
 	$walker = ( empty($r->walker) ) ? new Walker_Nav_Menu : $r->walker;
 	$args = array( $items, $depth, $r );
 
-	return call_user_func_array( array($walker, 'walk'), $args );
+	return call_user_func_array( array( $walker, 'walk' ), $args );
 }
 
 /**
@@ -665,11 +674,17 @@ function walk_nav_menu_tree( $items, $depth, $r ) {
  *
  * @since 3.0.1
  * @access private
+ *
+ * @staticvar array $used_ids
+ * @param string $id
+ * @param object $item
+ * @return string
  */
 function _nav_menu_item_id_use_once( $id, $item ) {
 	static $_used_ids = array();
-	if ( in_array( $item->ID, $_used_ids ) )
+	if ( in_array( $item->ID, $_used_ids ) ) {
 		return '';
+	}
 	$_used_ids[] = $item->ID;
 	return $id;
 }
diff --git a/src/wp-includes/nav-menu.php b/src/wp-includes/nav-menu.php
index 2c610e80da..88922ccdd1 100644
--- a/src/wp-includes/nav-menu.php
+++ b/src/wp-includes/nav-menu.php
@@ -13,7 +13,7 @@
  * @since 3.0.0
  *
  * @param string $menu Menu ID, slug, or name.
- * @return mixed false if $menu param isn't supplied or term does not exist, menu object if successful.
+ * @return object|false False if $menu param isn't supplied or term does not exist, menu object if successful.
  */
 function wp_get_nav_menu_object( $menu ) {
 	if ( ! $menu )
@@ -65,6 +65,8 @@ function is_nav_menu( $menu ) {
  *
  * @since 3.0.0
  *
+ * @global array $_wp_registered_nav_menus
+ *
  * @param array $locations Associative array of menu location identifiers (like a slug) and descriptive text.
  */
 function register_nav_menus( $locations = array() ) {
@@ -78,6 +80,8 @@ function register_nav_menus( $locations = array() ) {
 /**
  * Unregisters a navigation menu for a theme.
  *
+ * @global array $_wp_registered_nav_menus
+ *
  * @param string $location The menu location identifier.
  * @return bool True on success, false on failure.
  */
@@ -99,7 +103,7 @@ function unregister_nav_menu( $location ) {
  *
  * @since 3.0.0
  *
- * @param string $location Menu location identifier, like a slug.
+ * @param string $location    Menu location identifier, like a slug.
  * @param string $description Menu location descriptive text.
  */
 function register_nav_menu( $location, $description ) {
@@ -109,6 +113,9 @@ function register_nav_menu( $location, $description ) {
  * Returns an array of all registered navigation menus in a theme
  *
  * @since 3.0.0
+ *
+ * @global array $_wp_registered_nav_menus
+ *
  * @return array
  */
 function get_registered_nav_menus() {
@@ -134,6 +141,7 @@ function get_nav_menu_locations() {
  * Whether a registered nav menu location has a menu assigned to it.
  *
  * @since 3.0.0
+ *
  * @param string $location Menu location identifier.
  * @return bool Whether location has a menu.
  */
@@ -220,7 +228,7 @@ function wp_delete_nav_menu( $menu ) {
  *
  * @since 3.0.0
  *
- * @param int $menu_id The ID of the menu or "0" to create a new menu.
+ * @param int   $menu_id   The ID of the menu or "0" to create a new menu.
  * @param array $menu_data The array of menu data.
  * @return int|WP_Error Menu ID on success, WP_Error object on failure.
  */
@@ -298,9 +306,9 @@ function wp_update_nav_menu_object( $menu_id = 0, $menu_data = array() ) {
  *
  * @since 3.0.0
  *
- * @param int $menu_id The ID of the menu. Required. If "0", makes the menu item a draft orphan.
- * @param int $menu_item_db_id The ID of the menu item. If "0", creates a new menu item.
- * @param array $menu_item_data The menu item's data.
+ * @param int   $menu_id         The ID of the menu. Required. If "0", makes the menu item a draft orphan.
+ * @param int   $menu_item_db_id The ID of the menu item. If "0", creates a new menu item.
+ * @param array $menu_item_data  The menu item's data.
  * @return int|WP_Error The menu item's database ID or WP_Error object on failure.
  */
 function wp_update_nav_menu_item( $menu_id = 0, $menu_item_db_id = 0, $menu_item_data = array() ) {
@@ -486,6 +494,8 @@ function wp_get_nav_menus( $args = array() ) {
  * @since 3.0.0
  * @access private
  *
+ * @global string $_menu_item_sort_prop
+ *
  * @param object $a The first object to compare
  * @param object $b The second object to compare
  * @return int -1, 0, or 1 if $a is considered to be respectively less than, equal to, or greater than $b.
@@ -522,10 +532,7 @@ function _sort_nav_menu_items( $a, $b ) {
  * @return bool False if invalid, otherwise true.
  */
 function _is_valid_nav_menu_item( $item ) {
-	if ( ! empty( $item->_invalid ) )
-		return false;
-
-	return true;
+	return empty( $item->_invalid );
 }
 
 /**
@@ -533,9 +540,12 @@ function _is_valid_nav_menu_item( $item ) {
  *
  * @since 3.0.0
  *
+ * @global string $_menu_item_sort_prop
+ * @staticvar array $fetched
+ *
  * @param string $menu Menu name, ID, or slug.
  * @param array  $args Optional. Arguments to pass to {@see get_posts()}.
- * @return mixed $items Array of menu items, otherwise false.
+ * @return false|array $items Array of menu items, otherwise false.
  */
 function wp_get_nav_menu_items( $menu, $args = array() ) {
 	$menu = wp_get_nav_menu_object( $menu );
@@ -782,9 +792,9 @@ function wp_setup_nav_menu_item( $menu_item ) {
  *
  * @since 3.0.0
  *
- * @param int $object_id The ID of the original object.
+ * @param int    $object_id   The ID of the original object.
  * @param string $object_type The type of object, such as "taxonomy" or "post_type."
- * @param string $taxonomy If $object_type is "taxonomy", $taxonomy is the name of the tax that $object_id belongs to
+ * @param string $taxonomy    If $object_type is "taxonomy", $taxonomy is the name of the tax that $object_id belongs to
  * @return array The array of menu item IDs; empty array if none;
  */
 function wp_get_associated_nav_menu_items( $object_id = 0, $object_type = 'post_type', $taxonomy = '' ) {
@@ -868,8 +878,7 @@ function _wp_delete_tax_menu_item( $object_id = 0, $tt_id, $taxonomy ) {
  *
  * @param string $new_status The new status of the post object.
  * @param string $old_status The old status of the post object.
- * @param object $post The post object being transitioned from one status to another.
- * @return void
+ * @param object $post       The post object being transitioned from one status to another.
  */
 function _wp_auto_add_pages_to_menu( $new_status, $old_status, $post ) {
 	if ( 'publish' != $new_status || 'publish' == $old_status || 'page' != $post->post_type )