I had no idea ...
It started life as the emblem of the British anti-nuclear movement but it has become an international sign for peace, and arguably the most widely used protest symbol in the world.
... settled on using letters from the semaphore - or flag-signalling - alphabet, super-imposing N (uclear) on D (isarmament) and placing them within a circle symbolising Earth.
World's best-known protest symbol turns 50
Floating about somewhere, no doubt.
All we are saying is give uclear/isarmament a chance.
Videos