Mixed franking from postage due stamps from kingdom Yugoslavia over 0, 50 Din. With 1 Din. (strip of three) on unfree mailed domestic letter from Court in Zemun to Belgrad with dispatch stamp ZEMUN 1 / 16 from 2.6.41 as well with censorship stamp 63 the censor office Belgrad and arrival postmark BEOGRAD 25 / 21 from 24.6.41 on the postage due stamps and return shipment to Zemun. Because the postage due not takes the money become could, are the postage due stamps with blue pencil nullifys and turned back become. The cover point at traces on and has at the bottom defects from opening the cover. Certificate Dr. Zydek: "covers with a such (postage) franking are extraordinarily rare. "