When World War II broke out the Germans ordered the Jews to wear a special mark to show that they were Jewish.
In certain areas the Jews had to wear a yellow star, in the shape of a Star of David, on their chest. In other areas they had to wear a white band on the sleeve with a blue Star of David.
The marking of Jews was an obtrusive and humiliating decree which enabled easy identification of the Jews, and separated them from the rest of the population. Jews who refused to wear the mark, were punished.