In CA Servcie Desk when the Licensed flag is not checked in the Access Type for the Employee interface the users can check the requests with this constraint: (customer=CST.ID). They can follow tickets where they are the Affected End Users. But users can be Requester, too. They can be interested in tickets where they are the Requester but the Affected End User is different. These kind of tickets cannot be queried in the ScoreBoard. It is a common question from our customers.
The internal constraint would be better so: (requested_by=CST.ID or customer=CST.ID)