Serial number
Duck, especially the pressed duck, is the speciality (Canard à la presse, Caneton à la presse, Caneton Tour d'Argent, and recently renamed “Caneton de Frédéric Delair”). The restaurant raises its ducks on its own farm. Diners who order the duck receive a postcard with the bird's serial number, now well over 1 million. (Serial number #112,151 went to U.S. President Franklin Delano Roosevelt, #203,728 went to Marlene Dietrich, and #253,652 went to Charlie Chaplin).