Add a Notification to the Item form to show that there is an Alias for this item in the system. This should appear right next to the Name/Number field on the Item Form. Additionally, there should be a column in the items list with a check box if an item has an Alias in the system.
Item alias’s are a great feature! You can keep track of different vendors for this item and each vendor’s part number and price. However, you never know if an item has an Alias unless you drill into the menu item “Alias” for that item.