Julius
Looking at another of Tracy's other post (http://scn.sap.com/thread/3598947) she's trying to use ACL. Hence needing to know the tables to write joins/queries to hit tables within ACL
I've seen ACL used and have had the fun experience of Auditors using Google to find tables to perform checks on without context of what has actually been implemented in their particular system.
Regards
Colleen