Provide a simpler alternate to PaceHTTPStatusCodes. The text for this was taken directly from the current Atom pub spec.
HTTP defines a richer standardize system of response codes that is widely understood and supported by a wide array of web-enabled software.
Section 2.2 would be written as follows:
The Trackback Protocol uses the response status codes defined in HTTP to indicate the success or failure of an operation. Consult the HTTP specification [RFC2616] for detailed definitions of each status code. It is RECOMMENDED that entities contained within HTTP 4xx and 5xx responses include an explanation of the error using natural language.
Backwards compatibility with previous TrackBack implementations.