RDEFINE STARTED (CICSTASK.CICSDAA2) STDATA( USER=(CICSDAA2) )
When you issue the START command to start CICSTASK with the job name CICSDAA2, MVS passes the procedure name (CICSTASK) and the job name (CICSDAA2) to obtain the userid under which this CICS application-owning region is to run. In the example shown above, the CICS region userid is defined as CICSDAA2, the same as the APPLID.