An OpenEdge application can explicitly prevent acknowledgement of a message by calling the setNoAcknowledge procedure of the Message Consumer object. (The Message Consumer object is passed as a parameter to the message-handling procedure.) The setNoAcknowledge procedure is typically used when the application wants to receive the same message again because of an error in processing it, or when receipt of a group of messages is to be signaled by explicit acknowledgement of only the last message in the group.