The German guards were referred to by POWs as "goons" and, unaware of the Allied connotation, willingly accepted the nickname after being told it stood for "German Officer Or Non-Com". German guards were followed everywhere they went by prisoners, who used an elaborate system of signals to warn others of their location. The guards' movements were then carefully recorded in a logbook kept by a rota of officers. Unable to stop what the prisoners called the "Duty Pilot" system, the Germans allowed it to continue and on one occasion the book was used by Kommandant von Lindeiner to bring charges against two guards who had slunk away from duty several hours early.