FWIW, page 10 of the sales brochure for the 1969 Barracuda, no doubt written by a draft card burner in a Beatle haircut, mentioned not only "Slickback" for a fastback with vinyl top, but also these:

"Drophead" for Barracuda convertible.

"Knockabout" for notchback with 6-cylinder and 3-speed column shift.

"Cuda 340/383", actual real things.

Prior pages pitched Formula S, Road Wheels (recall wheels), and numerous options.