https://en.m.wikipedia.org/wiki/Operation_Greif
...German soldiers, wearing captured British and U.S. Army uniforms and using captured Allied vehicles, were to cause confusion in the rear of the Allied line.
Reconnaissance patrols of three or four men were to reconnoiter on both sides of the Meuse river and also pass on bogus orders to any U.S. units they met, reverse road signs, remove minefield warnings, and cordon off roads with warnings of nonexistent mines.
As a result, U.S. troops began asking other soldiers questions that they felt only Americans would know the answers to in order to flush out the German infiltrators, which included naming certain states' capitals, sports and trivia questions related to the U.S., etc. This practice resulted in U.S. brigadier general Bruce Clarke being held at gunpoint for some time after he incorrectly said the Chicago Cubs were in the American League[7][8][9][10] and a captain spending a week in detention after he was caught wearing German boots. General Omar Bradley was repeatedly stopped in his staff car by checkpoint guards who seemed to enjoy asking him such questions.
Is there a programmatic equivalent of asking what league the Chicago Cubs are in?