The FCC today ruled that stations broadcasting "dead air" - with the transmitter on but "nobody talking" - are not required to run station identification announcements.
The decision involves WMCU-89.7 (now WKCP) in Miami. For many years WMCU was a religious station. Last fall, WMCU's owners decided to sell the station to American Public Media; the latter group flipped WMCU to a classical-music outlet. (replacing commercial station WTMI-93.1 which had switched to dance music, then rock, a few years back) Fans of the Christian music on WMCU filed objections to the sale of the station.
The relevant objection involved FCC regulation 73.1201, which requires stations to identify themselves with call letters and city-of-license once an hour. The complaints stated that for three weeks last October, (before Public Media acquired it) WMCU broadcast "dead air" - silence - with no identification announcements - in violation of 73.1201.
The station admitted to the broadcasts. However, they argued that the station was silent - was not on the air - and that nothing in the regulations required a silent station to identify itself.
Usually, the term "silent" has meant the station is off the air entirely - the transmitter is turned off, no signal at all is being broadcast. WMCU argues otherwise - that if no program is being broadcast, the station is silent.
The FCC bought it. They agreed that WMCU was officially off the air (even though the carrier was still being transmitted at 100,000 watts - for the purpose of carrying a subcarrier signal) and thus didn't need to ID.
Original FCC document: