3.1.5.5.2 Delete Acknowledged Express Messages

The protocol MUST delete each OutgoingMessagePosition (section 3.1.1.3.1.2) ADM element instance rOutgoingMessagePosition from the OutgoingMessageTable ADM element where rOutgoingMessagePosition.SequenceNumber is less than or equal to the SessionHeader.AckSequenceNumber field and rOutgoingMessagePosition.RecoverableSequenceNumber is set to 0x0000.