The phrase "London calling" was the call sign of BBC Radio during the Second World War. It later became the name of the BBC World Service's radio catalog listings. Strummer was definitely tapping into this on his song, making these reports of apocalypse out to be official news reports. In fact, "London Calling" was originally titled "News of Clock Nine," as Chris Salewicz, author of Strummer's biography, Redemption Song, noted. It was "a reference to the BBC TV news broadcast in [the late '70s] at nine each weekday evening." An earlier draft of the lyrics reveals that one line even went, "London calling news of clock nine / Birth control - there's a plot on it."