The Lincolnshire Poacher or E3 after its ENIGMA designation, was the nickname of a mysterious, powerful shortwave numbers station that used two bars from the English folk song "The Lincolnshire Poacher" as an interval signal. The radio station was believed to be operated by the British Secret Intelligence Service and emanated from the island of Cyprus. Amateur direction finding had linked it with the Royal Air Force base at Akrotiri, Cyprus, where several curtain antennas had been identified as being its transmitter. It consisted of an electronically-synthesised English-accented female voice reading groups of 5 numbers: e.g. '3-9-7-1-5'. The final number in each group was spoken with a lifted voice. It is likely that the station was used to communicate to undercover agents operating in other countries (known as illegals), to be decoded using a one-time pad.
An Asian numbers station of identical format is believed to be broadcast from Guam, and nicknamed "Cherry Ripe". It uses several bars from the English folk song of the same name as its interval signal.
As of July 2008 the Lincolnshire Poacher seems no longer to be active, although its sister station Cherry Ripe has continued to be as of September 9, 2008.
- "Profile of The Lincolnshire Poacher", Spynumbers, 
- Ary Boender: "Lincolnshire Poacher", Numbers and Oddities, 
- Simon Mason: "The Lincolnshire Poacher", 
- "Profile of Cherry Ripe", Spynumbers, 
- E03 recording on YouTube.com