WAIT | NOWAIT are mutually exclusive, optional parameters used to specify whether to wait for the HRECOVER command to complete.

WAIT specifies that you want to wait for the HRECOVER command to complete. When DFSMShsm successfully completes the HRECOVER process, the ARC1000I message is issued. If the HRECOVER process does not complete successfully, the ARC1001I message is issued. If you press the TSO Attention key before DFSMShsm completes the command, DFSMShsm issues the ARC1800I message and does not issue the ARC1000I message.

NOWAIT specifies that you do not want to wait for the HRECOVER command to complete. When DFSMShsm successfully receives the request, the ARC1007I message is issued. If you are recovering data sets from tape, a volume mount request message (ARC0612I) is issued. After DFSMShsm successfully completes the HRECOVER command, the ARC1000I message is issued. If the HRECOVER command does not complete successfully, the ARC1001I message is issued.