Return codes

Register 15 contains a return code indicating the success or failure of the request. Possible return codes (in decimal) are:
0
The Preinitialization environment mask has been returned.
4
Non-valid function code.
8
CEEPIPI was called from an active environment.
16
The token is not valid.
20
The PreInit table entry indicated by ceexptbl_index was empty.
24
The index passed is outside the range of the table.