All reason codes are documented in the mfpubspl interface structure, in a section labeled Reason codes. For example:
*=================================================================
* Reason codes
*=================================================================
88 ()-INVALID-FUNC VALUE 01.
88 ()-INVALID-INDEX-ID VALUE 02.
88 ()-INVALID-SPOOL-VERSION VALUE 03.
88 ()-INVALID-SPOOL-LOCATION VALUE 04.
88 ()-EOF VALUE 10.
88 ()-BAD-OPEN-STATUS VALUE 11.
88 ()-BAD-CLOS-STATUS VALUE 12.
88 ()-BAD-GN-STATUS VALUE 13.
Match the returned reason code value to that of a reason code constant in the copybook. The field name provides the description of the code. The current file status code and name will be returned in the fields that immediately follow the reason code in the interface data structure.