Such emblems helped guards assign tasks to the detainees: for example, a guard at a glance could see if someone were a convicted criminal (green patch) and thus likely of a "tough" temperament suitable for kapo duty. Someone with an "escape suspect" mark usually would not be assigned to work squads operating outside the camp fence. Someone wearing an F could be called upon to help translate guards' spoken instructions to a trainload of new arrivals from France.