acronyms - "An RV" or "a RV"?

I am writing about Random Variables, which I am abbreviating to RV. Should I write 'an RV' (an Arr-Vee) or 'a RV' (a Random Variable)?

Answer

This depends entirely on how you expect people to read the letters RV. If you expect them to say "random variable" every time, then use a RV. If you expect that they'll pronounce the letter names, use an RV. Personally, I would lean towards the latter.

That's because the choice of a or an is determined entirely by pronunciation.