MENU_LOCAL_TASK
in includes/menu.inc
Menu type -- A task specific to the parent item, usually rendered as a tab.
Local tasks are menu items that describe actions to be performed on their parent item. An example is the path "node/52/edit", which performs the "edit" task on "node/52".
<?php
define('MENU_LOCAL_TASK', MENU_IS_LOCAL_TASK);
?>