The Zapple doctrine pertained to a particular sort of political speech in the United States, for which a candidate or his supporters bought air time but the candidate himself did not actually participate in the broadcast. The content could be supportive of the candidate, or be used to criticize his political opponent(s). It went into effect in 1970.
The Zapple doctrine came into existence as an addition to the FCC fairness doctrine. The fairness doctrine was a Federal Communications Commission (FCC) policy instated in June 1949. It required broadcasters to present multiple viewpoints about controversial matters of public importance. For the first time, radio station licensees were permitted to editorialize, but only if two or more perspectives were included.[1] (The fairness doctrine replaced the previous Mayflower doctrine, which did not allow any editorial content at all.[2])