Return Codes

The exit sets the return code in Register 15 (R15) before returning control to CA VM:Tape. The return code must be one of the following:

0: Continue the mount and apply its normal label processing to the mount
4: Continue the mount and unconditionally bypass label processing. Set this return code if the exit does its own label verification and determines that the label is correct
8: Unload the tape currently mounted by the operator indicated by message 092E and reissue the mount message
12: Cancel the MOUNT request, and send the user message VMT051T, indicating that the mount was canceled by USREXIT3