What "makes" a 66 Barracuda a Formula S ??

Well I had to respond. Back in 67 a friend wanted to ride around on my Honda Super Hawk, he said I could drive his 66 Formula S. It was a dog in my opinion (I don’t think he ever nailed it) but cool to drive. Next the lead singer in a band bought a 67 FS notch Barracuda, all we did was ride around looking for a race, 396 Cameros and Chevelles, Mustangs, GTOs. beat them all! I got to drive it but he wouldn’t let me race anyone, he was a good singer too! White with red interior four speed, engine screamed!