MENU_SUGGESTED_ITEM
in includes/menu.inc
Modules may "suggest" menu items that the administrator may enable. They act just as callbacks do until enabled, at which time they act like normal items. Note for the value: 0x0010 was a flag which is no longer used, but this way the values of MENU_CALLBACK and MENU_SUGGESTED_ITEM are separate.
<?php
define('MENU_SUGGESTED_ITEM', MENU_VISIBLE_IN_BREADCRUMB | 0x0010);
?>