The purpose of the exit program created by the user is to determine whether a user's access request is to be accepted or rejected. It does so using the values that are passed to it in the parameter list.
The program can be written to verify all the values in the parameter list, or to verify part of them. The program must return a return code of 1 to indicate that the request is accepted, and it should return a 0 to indicate that the request is rejected.
The user exit program processes on the target DDM or DRDA® server and must be located in a library in the system database (SYSBAS) if the target server is using independent auxiliary storage pools (independent ASPs).