MSGDSC (MQMD) - input/output

Message descriptor.

This structure describes the attributes of the message being sent, and receives information about the message after the put request is complete. See MQMD - Message descriptor for details.

If the application provides a version-1 MQMD, the message data can be prefixed with an MQMDE structure in order to specify values for the fields that exist in the version-2 MQMD but not the version-1. The MDFMT field in the MQMD must be set to FMMDE to indicate that an MQMDE is present. See MQMDE - Message descriptor extension for more details.