What cam to use in a 318

I've never understood at what point an "RV" cam isn't an "RV" cam anymore. Or where one starts being an "RV" cam. It's just such a vague description. I think 3/4 cam is more specific. lol
look, alls i know is that the law states you can drink while underway in an RV as long as you're behind the sink. which begs the question: can you mount the sink to the dashboard?