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.
Either FR or PFP. "FR" just feels like another filler word. PFP... I'm too used to calling them "avatars", it just feels wrong and superfluous. I'm probably aging myself here.