Why didn't Chevrolet put a code to distinguish a SS optioned car in 1968?

Good Question but one that cant be answered , They deleted info on the trim tags for 68 and the only ways to prove what you might have is by tell tale signs ( engine codes and dates that match, Trans numbers that match, 12 bolts that match, things like that that all match up with the serial Numbers ) Build sheets are proof on LA cars. But why Chevy left the 68 Trim tags so Vague is something we may never know.