While incarcerated at Spangenberg castle, Germany, as a prisoner-of-war, Major Alexis Casdagli passed the time by indulging himself in the hobby of embroidery.
The Nazis liked his work so much that they displayed it at several of the camps Major Casdagli was interred during the war.
What they failed to notice however was the morse code hidden in full view, as a part of the design, that spelled
out the phrases, "God Save the King" and "Fuck Hitler!".