I'd second Brian's call not to get into the document format game. Microsoft
RTF is not the world's greatest format, but it's not too bad either. At
least the syntax is consistent, which makes it fairly easy to parse. You can
get a document describing it from Microsoft. Sure it's more complicated than
your RICHTEXT format, but it gives you more also, not the least of which is the
advantage that there are millions of programs out there right now that
produce it.
I also don't think it belongs in RFC-XXXX. This definitely reeks of the "but
it's so easy, let's just sneak it in" school of design. I'm well-attuned to
that since I'm guilty of it all the time. But it doesn't make it right....
Terry