All UDEs 1200 and all MDEs 1202 provided by the preferred embodiment may, if desired, (as shown in FIG. 16) be stored in a common physical table within secure database 610, and database access processes may commonly be used to access all of these different types of data structures. [1208] In the preferred embodiment, PERCs 808 and user rights table records are types of UDE 1200.