Picture postcard for use by foreign tourist, has mark, imprinted on its front side, optically detectable as indication signal in such a manner that postcard is detected as post-paid postcard, where signal is machine-readable
摘要
<p>The postcard (10) has a flat front side imprinted with a picture theme (12), and a back side to be labeled. A mark (14) is imprinted on the front side, and is optically detectable by a machine as an indication signal in such a manner that the postcard is detected as post-paid postcard. The indication signal is a machine-readable signal. The mark is formed as an edge strip that is distinctive from rest of the picture theme, where the edge strip is dichromatic in design.</p>
