ToolTalk messages are simple structures that contain fields for address, subject, and delivery information. To send a ToolTalk message, an application obtains an empty message, fills in the message attributes, and sends the message. The sending application needs to provide the following information:
Is the message a notice, a request, or an offer? (that is, should the recipient respond to the message?)
What interest does the recipient share with the sender? (for example, is the recipient running in a specific user session or interested in a specific file?)
To narrow the focus of the message delivery, the sending application can provide more information in the message.