Require the use of the charset parameter of the Content-Type header.
Transmission of the payload is currently unreliable because the client is not required to inform the server of which character encoding is used. The proposal attempts to solve this problem by requiring the client to specify which character encoding is used, which allows the server to properly interpret the payload.
The second paragraph of section 2.1 would be written as follows:
Clients MUST transmit the character encoding of the entity payload using the charset parameter of the Content-Type header.
Backwards compatibility with previous TrackBack implementations. Implementations which do not specify the charset parameter of the Content-Type header are no longer compliant with the specification.