The Nazis defined three camp levels (I, II and III) to categorize the severity of imprisonment in a specific concentration camp. A letter from January 1941 stipulated how prisoners should be assigned to the camps. Level I prisoners (“protective custody prisoners who are minimally incriminated and absolutely capable of improvement”) were to be sent to Dachau and Sachsenhausen. Level III prisoners, by contrast, were considered “severely incriminated, and especially previously convicted, explicitly antisocial and thus scarcely educable.” They were to be imprisoned in Mauthausen. As this regulation would have resulted in many prisoners being transferred from one camp to another, it was effectively abolished in early 1942 by the Concentration Camps Inspectorate.