“john has a long mustache”
It sounds like a joke.
It was a message.
What It Is
“John has a long mustache” is a documented example of the personal messages the BBC broadcast to the French Resistance during the Second World War.
The phrase meant something only to the resistance group expecting it.
Everyone else heard a strange sentence on the radio and moved on.
Why It Works
A message that sounds meaningless draws no attention.
A message agreed in advance needs no explanation.
That combination is the whole trick.
Three Appearances
| Phrase | Where It Appears | What It Does |
|---|---|---|
| John has a long mustache | Radio Londres, The Longest Day, Red Dawn | Signals a pre-arranged action |
| The chair is against the wall | Red Dawn | Meaning never revealed |
| Long sobs of autumn violins | Radio Londres, June 1, 1944 | Invasion within two weeks |
| Wound my heart with monotonous languor | Radio Londres, June 5, 1944 | Action within 48 hours |
Go Deeper
From The Longest Day To Red Dawn
Sources
Radio Londres, Wikipedia
Ici Londres, WW2 Escape Lines Memorial Society
The BBC’s Coded Messages to the French Resistance, War History Online