Mine is OOO for Out Of Office. I always misread it in my head like a ghost and it takes me a few seconds to process. It also doesn’t translate to speech—you have to say the whole thing.
Interested to see if others have similar acronyms they beef with.
I never understood why it’s called double-u. It looks more like a double-v. Most of the time, the sound in words is even more similar to a V than a U. There is probably some reason in ancient versions of the letters.