MENU_ITEM_GROUPING
in core/includes/menu.inc
Item groupings are used for pages like "node/add" that simply list subpages to visit. They are distinguished from other pages in that they will disappear from the menu if no subpages exist.
<?php
define('MENU_ITEM_GROUPING', MENU_VISIBLE_IF_HAS_CHILDREN | MENU_VISIBLE_IN_BREADCRUMB | MENU_MODIFIABLE_BY_ADMIN);
?>