The classic 1965 big screen adaptation of Len Deighton’s cold war spy thriller The Ipcress File contains coded messages throughout. The film, produced by Bond impresario Harry Saltzman, which stars Michael Caine in the role of working class British Agent Harry Palmer and was directed by Sidney J. Furie in stylish 60s chic with pop art camera angles and minimalist music by John Barry, is layered with cryptic statements and hidden ciphers.

Together with surreptitious references to Lee Harvey Oswald and dark broodings on the Royal Family, the most famous series of messages comes in the Hyde Park bandstand scene when Major Dolby, played by Richard Green – who also starred alongside Caine in seminal native-bashing flick Zulu – beats Morse code out of time to the tune of 'The British Grenadier'. Keen-eyed viewers have deciphered that Green actually spells out all the names of the Grand National winners between 1973 and 1981 (except for 1976 when the Major only managed to forecast the second placed horse).