KATTOWITZ, German Empire postal stationery card 10 Pfg carmine-red Germania 1917 with added 20 Pfg blue Numeral issue 1920 to Berlin, double-circle KATTOWITZ 16 6 20 * (OBERSCHL.) f (OS handbook No. 141.9), use of German Empire stationery technically prohibited but not challenged by postal administration, unusual, neat strike, age and use marks typical of period