In my WIP there comes a point where the characters decide to do something on their own... (I dont know how and why they get to do this, but they do, they just make their own decisions and don't ask me.) What they have done is shorted an acronym I told them to use which is (FVNG). But because the characters (again, they all thought this up on their own) don't want to walk around all day and say, "Are you running the FVNG?" or "Are you going to start the FVNG or should I?" They would like to say just "FV" which to my MC sounds like they are saying (for the first time she hears it) "F.E." or "FE" or "effee"... So my question is how do I write "FE" and or "FV" to make it come across to the reader what they are saying? I suppose like dictionaries show words, sound it out? Does that make sense? Thanks... (Don't blame me, my characters just run away with all kinds of ideas that make my life hell).
You could go with an unreliable narrator and have your mc hear "Effie" - like the name. I wouldn't wait long to clear up the confusion, though. Or be more direct, just use 'FV', but have your mc go "FE?" to indicate that she heard it wrong.
I think I will have her hear "Effie" for the first time, then someone will clear it up for her. "What is an effie?" "An effie?" "Yea, the nurses on the floor were using that word. Is it a medical term?" "Ah an FV... short for FVNG, which is the Facilitated Verification of Networked Genetics." I may go with something like that...