Under FCC rules and federal law, radio stations and over-the-air television channels cannot air obscene material at any time, and cannot air indecent material between 6 a.m. and 10 p.m. The FCC defines obscene material as describing sexual conduct "in a patently offensive way" and lacking "serious literary, artistic, political or scientific value." Indecent material is not as offensive but still contains references to sex or excretions.