system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: how the Nazi identify the Jews in the holocaust

I mean, just by accusation? Did they had a census or anything? In the common cold war dictatorships delation or previous political activities were the cannon for getting people into trouble, but in the Nazi regime the idea was to delete an entire ethnical and cultural belief, so I can't figure it out.
gpt
The Nazi party in Germany identified Jews through military records, census records, tax returns, synagogue membership lists, parish records (for converted Jews), routine but mandatory police registration forms; the questioning of friends, relatives, neighbors, businesses was also used, as well as Jewish community membership lists, individual identity papers, captured census documents, police records, and local intelligence networks. 

When we think about the holocaust, or read about it, or hear about it, the focus is usually on the apex, the peak of the horror...but you have to understand that this happened gradually over a period of years. There were a number of methods employed to identify and exclude European Jews (amongst others), and it began with giving the power to Hitler and those who would follow him. In 1933, Germany passed the Enabling Act, which essentially ended democracy in Germany, giving the government the power to enact legislation by decree. This gave them the legal ability to make the discriminatory policies that were to come. It also meant Hitler was allowed to make legislation that violated the Weimar Constitution without the approval of the parliament. They began by suspending the licenses of Jewish doctors and others in service industries. They forbade Jews from taking the bar exam, thus preventing them from becoming lawyers. They used a claim of overcrowding in schools and Universities to prevent Jewish students from attending public schools. They then taught students to love Hitler, obey authorities, and hate Jews. All of this happened in 1933, and it was just the first steps. By 1934, Jews were prohibited from slaughtering animals, which prevented them from obeying Jewish dietary laws. Nearly every aspect of Jewish life was subject to arbitrary-seeming legislation. In 1935, the Nazi leaders announces the Nuremberg Laws. These laws (among other things) excluded Jews from having citizenship, from marrying or even having sex with German women, denied Jews basic political rights including voting, denied Jews the right to hold political office. They also made it nearly impossible for Jews to make a living, reducing Jewish-owned businesses in Germany by two-thirds. 

And so it went, until things finally got so horrific the rest of the world was forced to stand up and take notice and, more importantly, to act. It took far too long for that to happen, with a near global Depression making for hostile times all around.