Ka-tzetnik
Ka-tzetnik (KZ-nik) was short for 'concentration camp designate' (or inmate) to refer to Jews imprisoned in camps during the Holocaust. It was followed by a number, and this designation was tattooed on the forearm of Jews processed into the camps.Some survivors today still bear the mark, (written K.Z.000000), and one survivor, writer-historian Yehiel Dinur, wrote his books under a penname Ka-Tzetnik 135633, after his Nazi designation. His work documents the history of Nazi atrocities.