The default request type for the IXZXIXSM macro is REQTYPE=COMM. COMM indicates that the message being sent is communicated asynchronously, the sender does not request an acknowledgement, and JES XCF does not attempt multisystem recovery if either the sending or receiving member fails prior to message delivery.

This option is useful when the message data is informational only and there is no critical follow-on processing based on the acknowledgement.