Call sign

In broadcasting and radio communications, a call sign (also known as a call name or call letters—and historically as a call signal—or abbreviated as a call) is a unique designation for a transmitting station. In North America they are used as names for broadcasting stations. A call sign can be formally assigned by a government agency, informally adopted by individuals or organizations, or even cryptographically encoded to disguise a station's identity.

The use of call signs as unique identifiers dates to the landline railroad telegraph system. Because there was only one telegraph line linking all railroad stations, there needed to be a way to address each one when sending a telegram. In order to save time, two-letter identifiers were adopted for this purpose. This pattern continued in radiotelegraph operation; radio companies initially assigned two-letter identifiers to coastal stations and stations aboard ships at sea. These were not globally unique, so a one-letter company identifier (for instance, 'M' and two letters as a Marconi Station) was later added. By 1912, the need to quickly identify stations operated by multiple companies in multiple nations required an international standard; an ITU prefix would be used to identify a country, and the rest of the call sign an individual station in that country.

Call Signs

Call Signs is the third studio album by Melbourne electronica band Black Cab, released in 2009.

The album evokes the atmosphere of the former totalitarian state of East Germany, set to a soundtrack of post-punk and atmospheric electronics. In an interview, the band explained the album's sound was inspired by a rare Black Cab tour of Europe in May 2007. Travelling through the former East Germany in a van, vocalist Andrew Coates and guitarist James Lee were struck by the decrepit villages and rundown cities. At the same time they were reading Stasiland, Anna Funder's 2004 book about the vast state security apparatus that entangled millions of East Germans. Coates explained: "Stasiland really captured the mentality of living at a time when around 50 percent of East Germans contributed intelligence information, often about their neighbours. There was so much distrust and paranoia and it really interested us."

The album featured Died Pretty vocalist Ron Peno on one track, "Ghost Anthems".