Nazi mandated Star of David; Wikimedia Commons

In September 1941, all Jews over the age of six in the Third Reich and the ethnically Czech Protectorate of Bohemia and Moravia  were required to wear the Star of David with Jude (Jew in German) inscribed in faux Hebrew letters. This requirement was subsequently  introduced in other German-occupied areas.

Although the Nazis reinstated it, this practice was not new. Since medieval times, in both Christian and Muslim countries, persons not of the dominant religion were often required to wear badges, hats, bells or other items of clothing that distinguished them from the majority group.