This read-only INTEGER is the message number assigned by the sending module, since each module numbers its own message types as another way of identifying them, and this number can be cross-referenced in the CNT system messages reference manual. An admin unfamiliar with the exact wording of a message would use this number to look up the official explanation and recommended action in that manual. For example, quoting cntMsgNumber when contacting vendor support would let them immediately identify the exact condition being reported.