Auschwitz, as well as other concentration camps, identified prisoners by a number and/or a symbol. Prisoners were assigned a number upon arrival. Some prisons tatooed this number on the prisoners arm. Some prisons gave the prisoner a number patch that was to be sewn into the clothing. Each prisoner was identified by a unique number. The Nazi's kept excellent records and these numbers were used to track prisoners. The use of the number rather than a name helped to de-humanize the prisoner. A guard might be able to justify beating prisoner 54321 where he/she would have moral quams about beating prisoner John Smith, husband and father. We can see examples of this behavior in the book Night by Elie Weisel. Each prisoner also had a symbol or color assigned to them. These colors might differentiate between things like a political prisoner or a jewish prisoner. We see examples of this type of symbol used in the book The Hiding Place by Corrie Ten Boom.