According to the Third Geneva Convention of 1929 and its predecessor, the Hague Convention of 1907, Section IV, Chapter 2, those camps were only for prisoners of war, not civilians. Stalags were operated in both World War I and World War II and intended to be used for non-commissioned personnel (Enlisted ranks in US Army, Other ranks in British Commonwealth forces). Officers were held in separate camps called Oflag. In World War II, the German Air Force operated Stalag Luft in which flying personnel, both officers and non-commissioned officers were held. The German Navy operated Marlag for Navy personnel and Milag for Merchant Navy personnel.