Watch This When You're High - The Lincolnshire Poacher

Shout out to @mf1q2w3e for the suggestion on this one. Had never heard of this before, and upon reading the Wikipedia, I have no clue what to make of it. 

The Lincolnshire Poacher was a powerful British shortwave numbers station that transmitted from Her Majesty’s Government Communications Centre in Gawcott near Buckinghamshire, England, and later Cyprus, from the mid-1960s to June 2008. The station gained its commonly known name as it uses 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. Amateur direction finding 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 a pre-recorded English-accented female voice reading groups of five numbers: e.g., '0-2-5-8-8'. The final number in each group was spoken at a higher pitch. It is likely that the station was used to communicate to undercover agents operating in other countries, to be decoded using a one-time pad.

An Asian[clarification needed] numbers station of identical format is believed to have been broadcast from Australia, and nicknamed "Cherry Ripe". It uses several bars from the English folk song of the same name as its interval signal. Cherry Ripe ceased broadcasting in December 2009

Luckily there are a few decent videos that delve into it -

Keep the suggestions coming. Keep them classy. No butt stuff.