I have seen WBT Charlotte NC described as "Top 40" and even "rock" immediately after its big change in the 70s. But at some point those who decide format names called it "adult contemporary". I would think that right after the change, the first two were right, because morning host Ty Boyd is siad to have stormed into a superior's office and used language that would make a sailor blush. Hardly something one would expect from "adult contemporary", even after the station had been a full-service station playing songs that today would be called "adult standards".