The EXPIRINGMSG parameter controls the issuance of the WER901I message. The absence of the EXPIRINGMSG parameter or of the PARMS control statement in its entirety for a particular machine will cause the default (ON) to be put into effect.
When the WER901I message is written as a WTO, it will be written several times a day. The system will hold the message until it is deleted by the operator.