Using the RESPONSE and REASON options
The RESPONSE and REASON options are required on each API command.
You should specify these options as user-defined variables to receive the numeric response and reason values returned by a command. You can then convert the numeric values into more meaningful character equivalents. In general, RESPONSE describes the result of command processing and REASON further qualifies the response to certain commands.
Note: The TBUILD and TPARSE commands, which can be used only with the REXX
run-time interface, do not use the RESPONSE and REASON options. The result
of these REXX-specific processes is returned by their STATUS option. For more
information, see REXX error handling.