Sweden. Facit 71, 72 cover, 1+2×2 öre on printed matter sent during WW1 from LINKÖPING 7.6.15 to China. Undeliverable with cancel UNDELIVERABLE (ENEMY COUNTRY) RETURN TO SENDER. Transit pmk LONDON 16.JU.15. Slightly reduced in size with the upper back flap missing. Interesting item. Ex. Kvalitetsfilateli 1988.