This group includes data that is seen by the developer but not by the user. The user simply sees the data stored here as part of the system and does not manipulate it.
When setting up your environment, you may wish to collect all application-driving data in one central Application-Driving Tables library or you may wish to place it in specific Application-Driving Tables libraries. User data should not be placed in the Application-Driving Tables library as this library is often the subject of special RACF security. If this library becomes corrupt, tablesONLINE/CICS will not launch.