Sweden. Postal stationery, Double postcard, Facit bKd25, Reply-paid postcard 10+10 öre. The response card is additionally franked with 10×1 pf and sent with air mail, from GÖHREN (RÜGEN) 25.7.37. Interestingly, the originating card is not used. The two halfs partly separated. Very scarce impermissible usage.