Standardized surrender pass agreed to by the American and British psychological warfare units in 1944 and dropped by the millions on German troops from Allied aircraft. The facsimile signature of Dwight Eisenhower as Supreme Allied Commander gave it a very realistic touch.
Millions of these leaflets were air dropped on German troops in Western Europe once the Allies had invaded France and broken out of the beach head at Normandy (which took far longer than planned).
The surrender pass was printed in several colors on high quality paper so that it would appear to German soldiers as an approved, official document, which it was. No knows exactly how many Germans surrendered holding this leaflet but I have seen estimates as high as 900,000. It is impossible to know, of course.
Because the Allies dropped hundreds of millions of leaflets of every sort on the Germans, these specific surrender passes could not be printed on any other propaganda leaflets. The Allies wanted to preserve the official quality and look of this pass.
I’ve read various histories of psychological operations in World War Two. Many claim that of all propaganda leaflets dropped by the Anglo-Americans, this was the most effective.
There is absolutely no way to asses this claim so as a historian I would have to say we will never know if this was the most effective leaflet. But the anecdotal evidence is certainly convincing enough to say this was probably one of the most effective.