SOAR-ity is intended to allow for "reliable" (this term is almost always a misnomer) messaging over HTTP. It achieves this goal by introducing two new request headers, MID which provides a unique ID for a message and MsgCreate which contains the date and time on which the first instance of the message with the associated MID was sent. The purpose of the MID/MsgCreate pair is to allow any HTTP request (e.g. any HTTP method can be used) to be repeated multiple times with a guarantee that the message will be processed no more than one time. In essence it makes any HTTP method call idempotent.

The SOA-Rity specification is now available as an Internet Draft. Below I provide links to different versions of the draft that are hosted locally so as to ensure accessibility if the draft should expire.:

I'd also like to take this opportunity to say that the Oxygen editor ROCKS! Make sure to check out their 'academic licenses' which are actually just for personal use in case you can't justify buying Oxygen for your job.