The red triangle was a Nazi concentration camp badge worn in two instances. Worn upright, the badge was applied to prisoners of war, spies, and military deserters. As a red inverted triangle, the badge was worn by political prisoners. The Nazis chose red because the first people to have to wear it were Communists. Besides Communists, liberals, anarchists, Social Democrats, Freemasons, and other opposition party members also wore a red triangle. Many red triangle wearers were interned at Dachau concentration camp.