B/L (Bill of Lading)
The key sea freight document issued by the carrier, serving as a receipt for cargo, evidence of the transport contract and a document of title to the goods.
TL;DR: A Bill of Lading is the document a carrier issues when it takes cargo for ocean shipment. It works as a receipt, as evidence of the transport contract, and as a document of title that controls who can collect the goods.
The Bill of Lading, written B/L or BL, has three main functions. First, it is a receipt showing the carrier received the goods in the stated quantity and apparent condition. Second, it is evidence of the contract of carriage between the shipper and the carrier. Third, an original negotiable B/L is a document of title. Whoever holds it, properly endorsed, has the right to claim the cargo at the destination port.
Carriers usually issue a set of originals, often three, plus non-negotiable copies. Copies are for information only and cannot be used to release cargo. When originals are used, the buyer normally receives them after paying the seller, then presents one to the carrier or its agent to take delivery.
This link between documents and payment is why the B/L matters under T/T balance payments, L/C, and D/P. The seller keeps control of the goods until paid. Mailing originals by courier takes time, so many buyers use a Telex Release or a Sea Waybill instead when trust is established.
A clean B/L shows no remarks about damage. A claused B/L notes problems such as broken crates, which can affect L/C payment and insurance claims. Compare with MBL and HBL, Telex Release, and Sea Waybill.