You can add pop-up menus to shelf items to perform custom tasks. Pop-up menus appear when you right-click each shelf item.
To create a new pop-up menu
An entry called User Menu Item appears in the Menu Items list.
Now if you right-click the corresponding shelf item, your new menu item appears in the pop-up menu. If you select it, Maya performs the actions defined by the script.
You can modify a script at any time to adjust the functionality of your menu items. You can also adjust the order in which the items appear by reordering them with the Move Up (
) and Move Down (
) buttons. You can delete a menu item by highlighting it and clicking the Delete Menu Item (
) button.