PrF UG forms display slot
The Display Slot Menu
The Display Slot menu allows you to choose the display slot, used to identify the different instances when they are displayed in the Instance Browser or on a list.
If you do not select a slot to use as a display slot, Protege-Frames uses a default key, <instance name>, such as newspaper_0017. It is usually helpful to set a display slot.
If you set a display slot for a class, the slot is inherited by any subclasses.