Red Dawn borrowed its code from history. The real broadcasts came from London between 1940 and 1944, and they helped prepare the French Resistance for the Allied landings in Normandy.
The Station
Radio Londres was the French language service of the BBC. It went on the air in June 1940 with a first broadcast by Charles de Gaulle, and it carried news, music, comedy and encouragement to a country under occupation. Its most important job was quieter: carrying coded messages to agents and resistance groups.
The idea came from Georges Bégué, an operative with Britain’s Special Operations Executive. Short personal messages that sounded like trivia let agents receive orders without risky radio transmissions of their own. Broadcasts introduced them with a plain announcement that listeners should stand by for some personal messages.
The Messages
Each message belonged to one group or one operation. “Jean has a long mustache” was among the best known. The phrases seem absurd on purpose. Only the listener holding the matching code sheet knew whether a sentence meant a supply drop, a meeting or an order to act.
June 1944: The Poem Signal
On the eve of D-Day the BBC read lines from a poem by Paul Verlaine, “Chanson d’automne,” written in 1866. The first line, “Les sanglots longs des violons de l’automne,” told the Resistance that the invasion was near. The next line, “Blessent mon coeur d’une langueur monotone,” broadcast on the night of June 5, meant that the attack would begin within about two days and that sabotage teams, especially those targeting railways, should go into action.
By the start of June the airwaves carried hundreds of messages a day. Occupation forces could not decode them all, and jamming attempts only partly worked.
A Museum In The Bunker
The Verlaine Message Museum in Tourcoing, France, occupies the bunker where German forces intercepted the June 5 broadcast.
From London To Calumet
Red Dawn applies the same trick to an occupied America. “Radio Free America” speaks to the Wolverines through lines that mean nothing to the invaders. Read how the film uses it on The Code Phrases and write a broadcast of your own at Radio Free America.
More on the code: John Has A Long Mustache.com, the sister site.
Sources: Radio Londres, Verlaine Message Museum, Chanson d’automne, The Role of Radio in Wartime France.