Replace the proprietary and less functional status reporting messages with HTTP standard response codes as defined by RFC2616.
http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
Proposal
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:
Upon receipt of a TrackBack Ping Request, the Server MUST respond using an HTTP status code regardless of the result.
If a Ping was understood and processed the Server MUST respond with a 201 Created HTTP status code.
If a Ping was understood, but is being held for further processing, such as a moderator's approval, the Server MUST respond with a 202 Accepted HTTP status code.
If the Ping could not be processed due to malformed syntax such as a missing parameter the Server MUST respond with a 400 Bad Request HTTP status code.
If authorization or verification is required to process the Ping the Server MUST respond with a 401 Unauthorized HTTP status code. The client MAY choose to submit the ping again with valid credentials.
If the Ping was understood, but not accepted and authorization will not help, the Server MUST respond with a 403 Forbidden HTTP status code.
If the Ping uses an identifier that is not known to the Server it MUST respond with a 404 Not Found HTTP status code.
If the Ping was sent using an HTTP method other then POST the Server MUST respond with a 405 Method Not Allowed HTTP status code.
If the Ping is for a resource that is not accepting TrackBack pings the Server MUST respond with a 410 Gone HTTP status code.
Backwards compatibility with previous TrackBack implementations.