This read-create INTEGER is the third and final ACL-pointer slot a class map can use to add yet another ACL's criteria into the same traffic class. An admin reaches for this third slot only when a class needs to be defined by combining matches from three separate ACLs, for the most complex traffic-classification scenarios. For example, a class map covering several distinct voice-related traffic patterns spread across three separately maintained ACLs would use this third slot to reference the last of them.