However, is not forum owner - aka
theymos - task to say what
bitcointalk.org abbreviation should be used?
You can use whatever you want...
I almost always call this site "the forum", "the Bitcoin Forum", or "bitcointalk.org" (spelled out completely). I very rarely call it just "BitcoinTalk," so any abbreviation of that name isn't natural to me. I don't see where people get BTT from, though.