shrimp

I've come to understand what it means, it seems to mean that it's a personal weapon. So anyone who knows what Prf stands for? My guesses: 1. Personal-as-F (a little informal, but conveys exclusivity directly) 2. Preferred (but that doesn't really convey any exclusivity) I can't sleep because of this, I need more than guesses I need answer with 100% certainty.