Sweden, FRANCE, French boxed cancellation RETOUR A L'ENVOYEUR on Swedish stamp 30 öre Gustaf V right profile, together with boxed cancellation INCONNU, on window envelope. At back notation "Incononou Hotel ..." and with circle cancellation AIX LES BAINS SAVOIE 13\* 20.II.1950. Probably unique cancellation on Swedish stamp. (Image1)