3.12.5 Message Processing Events and Sequencing Rules
When a message arrives on the virtual channel reserved for chat, it is always assumed to be a NULL-terminated Unicode string. Because there can be only one possible sender, the message has no header and no packet information. Therefore, each packet MUST be considered a discrete message that SHOULD be displayed in its entirety to the receiving user. There are no error codes or responses expected or sent in response to receiving a chat message. Chat messages of a length greater than 1,024 bytes MUST NOT be sent by versions 2 or 3; version 1 allows messages longer than 1,024 bytes. Chat messages of a length greater than 1,024 bytes are not sent by versions 2 or 3, but they can receive messages longer than 1,024 bytes from version 1 clients.