HTTP Status 902 - No such conversation

Question

I was working with a colleague doing some work that involves passing callback URL's from my module to his. Because of some misconfiguration on his side, the call back URL was different and it called a URL from his server, not mine. Appart that we fixed the error, during that misconfigured callback I got this response (which I've never seen before):

HTTP Status 902 - No such conversation

Just out of curiosity I googled around and can not find any specification or description of this HTTP status code, and I always thought that status codes only went from 1XX to 5XX (As explained in Section 10 of the HTTP 1.1 Spec)

Any idea where I can find an official (or not) spec that describes this?

FYI the server in question is a Tomcat 7.0.25

EDIT: Including image of the response

Answer 1

There is no official spec defining this. (You can see the list of registered status codes here: http://www.iana.org/assignments/http-status-codes/http-status-codes.xml)