In foreign trade when export goods are loaded on board a ship or they delivered to placesin the shipping company's custody, the shipping company or its agent issues a bill of lading（B/L） to the shipper, acknowledging that the goods are shipped on board or received forshipment. A bill of lading, signed by the ship owner or his agent who contracts to carry the goods,and stating the conditions in which the goods were received by the ship, is a receipt of thegoods entrusted to him by the shipper for carriage to the designated destination. The bill oflading is an important sea transport document that, together with the insurance policy andcommercial invoices, constitutes the chief shipping documents indispensable to foreign trade.It is usually made out in sets of three or four originals and several extra copies. In addition tothe details referring to the goods and their destination a bill of lading contains a great numberof clauses stating the rights and obligations of the ship owner and shipper. One of the copiesof the bill of lading is retained by the shipping company, and the originals are returned to theshipper after they have been duly signed together with extra non-negotiable copies.