Non-negotiable B/L, also known as a Straight B/L, is a document issued by a carrier or their agent to acknowledge the receipt of goods and serve as evidence of the contract of carriage. Unlike a negotiable bill of lading, a non-negotiable bill of lading is not transferable to a third party through endorsement. It is typically marked "non-negotiable" or "not negotiable" to indicate that it is non-transferrable.