Prisoners were assigned to one of three categories depending on their qualifications: A, B or C. If A was written on a card, it meant that the person was an untrained, unskilled worker. Trained skilled workers were identified by a B. Cards with the category B often have an additional note of angelernt (“trained,” usually abbreviated as angel.) next to the prisoner’s occupation. A category of C was given to specialists who had received the relevant education before they were imprisoned.