REPLY-CARD with correct TWO-COUNTRY MIXED FRANKING. British ½d applied to German 5 pf. replycard in order to uprate the reply from the UPU printed matter rate to the UPU postcard rate. Such reply cards are the only possible correct occurence of two-country mixed frankings paying one rate post-UPU. A commercially used rarity!
Ægte blandingsfrankering mellem et engelsk frimærke og et tysk helsagssvarkort. Sjælden!