That rule is interesting. I had no idea.
As for no record of enforcement, it makes sense that without complaints there wouldn't be any. After all, the FCC isn't just sitting around listening to random radio stations to see whether there are violations: they depend on complaints. (For example, I've heard of socially conservative groups watching television to send in complaints about violations they see in the Simpsons, or whatever other shows offend their sensibilities.) If nobody on the listening or business end is submitting complaints about the issue, even FCC employees who are aware probably just don't care much.
As for no record of enforcement, it makes sense that without complaints there wouldn't be any. After all, the FCC isn't just sitting around listening to random radio stations to see whether there are violations: they depend on complaints. (For example, I've heard of socially conservative groups watching television to send in complaints about violations they see in the Simpsons, or whatever other shows offend their sensibilities.) If nobody on the listening or business end is submitting complaints about the issue, even FCC employees who are aware probably just don't care much.