Here 'tis, fresh outta my tubes:
http://en.wikipedia.org/wiki/Equal_timeThe equal-time rule specifies that U.S. radio and television broadcast stations
must provide an equivalent opportunity to any opposing political candidates who might request it. This means, for example that if a station gives one free minute to a candidate on the prime time, it must do the same to another.
However,
there are four exceptions: if the air-time was in a
documentary, bona fide
news interview,
scheduled newscast or an
on-the-spot news event the equal-time rule is not valid. Since 1983, political debates not hosted by the media station are considered news events, thus may include only major-party candidates without having to offer air time to minor-party or independent candidates.
This rule originated in § 18 of the Radio Act of 1927<1>. It was later superseded by the Communications Act of 1934, where the Equal Time Rule is codified as § 315(a).
Another provision of § 315(a) prohibits stations from censoring campaign ads. A related provision, in § 315(b), requires that broadcasters offer time to candidates at the same rate as their "most favored advertiser".
The rule was created because FCC thought the stations could easily manipulate the outcome of the elections.
The Equal-time rule is sometimes confused with the Fairness Doctrine.