They don't necessarily mean anything, but here are some ideas:RL = Road Luxury / Replaces Legend. (Legend is an Acura model name in Japan) http://en.wikipedia.org/wiki/Acura_RLTL = Touring Luxury (luxury touring car) / True LuxuryCL = Contemporary luxury / Coupe Luxury (luxury coupe)http://en.wikipedia.org/wiki/Acura_CL