I'd could also mean kurz. An SLK is both a smaller and a shorter SL, and a CLK is both a smaller and shorter CL. So I guess we're both theoretically right! Which one is the word that Benz had in mind, I can't remember.
I think dealers referring to the C coupe as a CL is idiotic since it is a totally different model obviously. Just call it a coupe!! C230 COUPE! Simple. And as far as the CK...Calvin Klein??