I think the main goal is to compete with OSI's much more defined model. I for one, don't want to see OSI overtake in any way TCP/IP, even in definitions. But Bill S. is correct, all you have to do is mention the layer and protocol. But there are so many new protocol's out there now, as I've mentioned before PPP is an example written since rfc 1122-23. It is now its own suite, with a family of link and network control protocols.