What is a C.A.P. option?

I'm looking in my 1967 manual under "cooling systems." I see various engines and options, and then there is a corresponding info on fan blade size, number of blades, water pump impeller, etc.

Options include None, A/C, Trailer Tow, and C.A.P. I can't see where C.A.P. is defined. It can apply to both A and B body cars.