Federal law prohibits obscene, indecent and profane content from being broadcast on the radio or TV.  That may seem clear enough, but determining what obscene, indecent and profane mean can be difficult, depending on who you talk to.
In the Supreme Court's 1964 landmark case on obscenity and pornography, Justice Potter Stewart famously wrote: "I know it when I see it."  That case still influences FCC rules today, and complaints from the public about broadcasting objectionable content drive the enforcement of those rules.
In other words, if you "know it when you see it" and find it objectionable, you can tell the FCC and ask us to check into it.