The NULLOUT option specifies the action to be taken when SORTOUT in a sort, merge, or copy application contains no data records. NULLOUT will be ignored for a BetterGener application.
RC0
The delivered default instructs MFX to issue a return code of 0 if not overridden by a higher return code set for another reason.
RC4
Instructs MFX to issue a WER461I warning message and continue processing. A return code of 4 will be issued if not overridden by a higher return code set for another reason.
RC16
Instructs MFX to issue a WER461A message and to terminate processing with a return code of 16.