Yeah, I believed it is based on the US Tri-service aircraft designation system although with some differences (a V in front would usually mean that the craft is a staff or VIP transport).
Based on what we've seen, the NUNS version probably goes like this: Modified mission + Status Prefix + Basic Mission + series number, e.g Luca's RVF-25 (R = reconnaisance, V = Variable, F = Fighter).
Makes you wonder if Misa learned from the Miria school of child care. Throwing babies
Well to your defense, Valkyrie became a sort of popular term for VF's in the Macross universe anyway.