What was the code name given to the plan for the final solution?

Operation Reinhard (Aktion Reinhard, Einsatz Reinhard, Aktion Reinhardt or Einsatz Reinhardt in German) was the code name given to the Nazi plan to murder Polish Jews in the General Government, and marked the beginning of the most deadly phase of the Holocaust, the use of extermination camps. During the operation, as many as two million people were murdered in Belzec, Sobibor, Treblinka and Majdanek, almost all of them Jews.