All IXLCACHE requests provide a return code in register 15. The system returns reason codes, if they exist, in register 0. (Not all return codes have reason codes.) Optionally, you can define the return code keyword (RETCODE) and the reason code keyword (RSNCODE) in your program.

If the IXLCACHE request defines an answer area, the answer area also contains the return code (in the CAARETCODE field) and the reason code (in the CAARSNCODE field).