Here is my first attempt at a more official CM15A protocol document. It's not done but it's much better than my confusing CM15D web page. The CM15D was just a loose notes page but we all tried to use it as much more. I decided that I should spend a little time and put my notes into document form and make the thing more understandable. I don't think this document is perfect but it's a little better than the CM15A page.
Over the next few months I'll spend more time cleaning up my other pages as well and update various packages I maintain. Since the loss of my drive in August I am still cleaning up the mess. I've added the above link to my documentation section of my we pages.