3.1.4.1 Sending a Chat Message

To send a chat message, a participant SHOULD send a TRANS_USERDATA_SEND_MESSAGE to the other participant. The TRANS_USERDATA_HEADER for the message SHOULD indicate that it is sequential and not reliable, that is, it SHOULD have the PACKET_COMMAND_SEQUENTIAL flag set, and SHOULD NOT have the PACKET_COMMAND_RELIABLE flag set in the bCommand field.