I've actually never been in the habit of calling them the proper R/V designation, I just stick to the C/K. Same with the 10/20/30 thing. It has sometimes caused confusion when I go to the parts store counter and forget to tell them the right model. I usually get "the computer doesn't list a K20 Suburban in '88" and then I remember my bad habit. On the other hand, if they say "do you mean a V20? then I know I'm dealing with a decent parts guy.