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.
There’s also WYGIWYW (“What You Get Is What You Want”) and is primarily used for latex, because you give up some manual control for a (allegedly) better looking result.