Identification of Jews
In November 1939, one year after Kristallnacht, the Nazi government followed the recommendation of leader Reinhard Heydrich and first introduced mandatory ID badges for Jews in Poland. It was announced that "severe punishment is in store for Jews who do not wear the yellow badgeon back and front."
Jews in the camps were identified by a yellow star sewn onto their prison uniforms, a mockery of the Jewish Star of David symbol. The Jewish people were required by the Nazis to wear the yellow Star of David in the camps and throughout most of occupied Europe.
http://shaeharrisholocaustproject.weebly.com/photography.html
This card was stamped with the letter "J" which stands for Jude (Jew). All Jews had to have this identification card on them at all times because on July 23 1928 a decree was passed that all Jews where to apply for an identification card. A month later, another law was applied saying that all male Jews had to take the name "Israel" and all female Jews had to take the name "Sara".
Everywhere a Jewish person turned, the Nazis had the goal to humiliate and persecute then. On all buildings that a Jewish person resided in had a sign that read "In diesem Grundstuck wohnen Juden." They put this sign on the building because it told everyone who passed by that a Jewish person lived there. Because of this sign, many German people who were friends with Jewish people stopped going around the Jewish neighborhoods.
http://www.yivo.org/library/index.php?tid=79&aid=208
Everywhere a Jewish person turned, the Nazis had the goal to humiliate and persecute then. On all buildings that a Jewish person resided in had a sign that read "In diesem Grundstuck wohnen Juden." They put this sign on the building because it told everyone who passed by that a Jewish person lived there. Because of this sign, many German people who were friends with Jewish people stopped going around the Jewish neighborhoods.
http://www.yivo.org/library/index.php?tid=79&aid=208