Class

• Use TT_REQUEST for messages that return values or status. You will be informed when the message is handled or queued, or when a process is started to handle the request.

• Use TT_NOTICEfor messages that only notify other processes of events.

• Use TT_OFFER for messages for which there are multiple intended recipients, and for which you wish to determine how many of those recipients have accepted, rejected, or abstained from participation in this message.