Postage due stamps world record letter, fourfold sent on and fourfold with postage due stamps franked cover. With 12 Pfg Hindenburg (corner fault) from "Brunswick 29.11.36" to Innsbruck-Mühlau / Austria, thence in the Czechoslovakia forwarded and there further three times forwarded. The cover was in Liberec, Komotau, Ground stream and in Prague with postage due stamps franked. An extraordinary document!