I think an indicator of a node's depth in a thread would be a good thing, but I don't think I'd care for anything as complicated as your proposal. I don't think that "3.4.1.5.1.2.3.1.1.1.3.1.1.1.2" would contain much more useful information than "Re15:" would.

-sauoq
"My two cents aren't worth a dime.";