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.
One that always confuses me is MSM. For over 40 years it has been used to mean “Men who have sex with men”, but recently conservatives started using it to mean “mainstream media” and its sometimes hard to tell which of their hates they are talking about. MSM is still widely used in the medical community when discussing/classifying patients and in the ongoing AIDS epidemic.