Military history buffs will recall that prior to the D-Day landings in 1944, there was consternation in security circles when some of the code-names for major elements of the operation appeared as solutions to crossword puzzle clues in the Daily Telegraph. The crossword compiler was actually arrested and questioned, but cleared of any wrongdoing.
Many years later, an explanation emerged. The Telegraph reports:
As part of the commemorations for the 40th anniversary of D-Day, the Telegraph revisited the crossword saga. Bill Deedes, then the paper’s editor, was alarmed by the scandal afresh, and instructed the puzzles editor to check that no codewords relating to the Falklands had appeared in the crossword during the recent conflict. None was found.
A few days later, Ronald French, another Old Strandian who had been encouraged by the renewed interest, wrote to the paper to admit to inserting the clues himself. [Leonard] Dawe [the crosswords' compiler], it emerged, would invite his pupils to fill in his blank crosswords with any words that came to mind. He would later devise clues to match the boys’ solutions.
With the war at its height, the excitable teenagers were obsessed by the vocabulary of the era, which is why other solutions of the time included “warden”, “Poland”, “aircraft” and “disarm”.
Likewise, the codewords were no coincidence. US and Canadian soldiers preparing for D-Day were camped close to the school, and the boys would regularly mix with them.
“The soldiers were obviously lonely,” recalls Bryan Belfont, a year below French. “Many had children of their own, and they more or less adopted us. We’d sit and chat and they’d give us chocolate.”
It was during one of these conversations that French heard the codewords. Security was remarkably lax, and he had struck up close friendships with the soldiers, regularly taking the colonel’s dog for a walk and even, on one occasion, driving a tank.
“Everyone knew the outline invasion plan and they knew the codewords,” he explained. “Omaha and Utah were the beaches, and they knew the names but not the locations. We all knew the operation was called Overlord.”
Perhaps to show off his knowledge, he slipped these words into the crossword. He bitterly regretted it, however, once he learnt of the trouble he had caused.
“Soon after D-Day, Dawe sent for me and asked me where I had got the words from. I told him and he asked to see my notebooks. He was horrified and said that the books must be burnt at once.
“He then gave me a stern lecture about national security and made me swear that I would tell no one about the matter. I have kept to that oath until now.”
There's more at the link.
Fascinating to learn that an episode I'd thought was overhyped and possibly apocryphal was, in fact, absolutely true.