See also: Add Item, Edit Item, Activate Item, Set Default Item, Re-order Items
You can inactivate an item from the existing items in the drop-down list, to hide it from display.
Steps:
Right-click the drop-down list.
Click Edit System List button.
In the Edit System List dialog box, select the item that you want to inactivate.
Check Inactivate check box.
Click Save
Click Close.