property Item.ID as Long
Retrieves or sets a value that specifies the item's identifier.

TypeDescription
Long A long expression that specifies the item's identifier.  

It is recommended to use unique identifier for the menu items, because the Find or Item property finds only the first item that matches the identifier. The identifier is not used by the control in any way, so it can be taken as a extra data as well. You can assign the item's identifier when you add new items using the Add method. Use the Debug property to display the item identifiers when the control is running. Use the Caption property to specify the caption of the item.