CLAIMED 1 of 1 '69 notch??????

What is a notchback, why the variation, and what years was a nothchback manufactured (limited edition or something)? Excuse my ignorance (have a '65 Formula S myself). Thank you.

67, 68 and 69. Notchback as opposed to Fastback. The fastback was the more sporty of the two and more popular for some strange reason. Maybe it was the psychedelics of the late sixties.