The preserved records of the Reichssicherheitshauptamt (the Reich Security Main Office) show the persecution of Freemasons during the Holocaust. RSHA Amt VII (Written Records) was overseen by Professor Franz Six and was responsible for "ideological" tasks, by which was meant the creation of antisemitic and anti-Masonic propaganda. While the number is not accurately known, it is estimated that between 80,000 and 200,000 Freemasons were killed under the Nazi regime. Masonic concentration camp inmates were graded as political prisoners and wore an inverted red triangle.
What identifier did the Nazis make the Freemason prisioners wear?
{'text': 'inverted red triangle', 'answer_start': 551}