From November, 1916, onwards, French pilots were issued metal wings by the flight schools from which they had graduated, each of which was prefaced with an elaborate, capital “B” followed by a serial number which was hand-struck and quite small, measuring only 1.5 mm in height; 7,000 of these were issued numbered 1 through 7,000 and then the die was changed to 2.0 mm in height and this was used through 15,000 at the end of the war. After the war, the “B” prefix was dropped and the serial numbers doubled in height to about 4 mm. The photo below shows N° B.3280 with the 1.5 mm high die. During the Second World War, the records of which numbers were issued to specific schools and from those schools to specific pilots disappeared. Pilots were also issued a numbered, paper certificate called a Brevet D'Aviateur Militaire; the numbers on these certificates did not match the number stamped on the metal wing.