To use a return code and reason code that are set in the postprocessing exit, you must set bit 2 in Offset +20 of EXPB. Setting bit 2 on causes ICSF to return the return code from the exit in register 15 and the reason code in register 0. Even though the application program receives the codes from the exit in the registers, the program still receives the codes from the service in the parameter list. The return code is the first parameter, and the reason code is the second parameter in the list.

Some control languages can access registers more easily than others. For this reason, ICSF allows you to return the return code and the reason code in both the registers and the parameter list. To do this, set bit 5 as well as bit 2 in Offset +20 of EXPB. The application then receives the return code and the reason code from the exit in both the registers and the parameter list.

If you do not set either of or both of the flag bits, the service ignores any return or reason code from the exit. The application program receives the codes from the service in both the registers and the parameter list.

The exit can pass back any valid return code for each service. For a listing of each service's return codes, see z/OS Cryptographic Services ICSF Application Programmer’s Guide.