A more thorough explanation:

An unclean bill of lading is a document that acknowledges the receipt of goods by a carrier or shipper's agent and the contract for the transportation of those goods. It shows on its face that the goods were damaged or that there was a shortage of goods at the time of shipment. This is different from a clean bill of lading, which contains no clause or notation qualifying the bill's terms.

For example, if a shipment of electronics arrives at its destination with some items missing or damaged, the bill of lading for that shipment would be considered unclean. This document would show that the carrier received the goods in a damaged or incomplete state.

An unclean bill of lading can cause problems for the shipper, as it may affect their ability to receive payment for the goods or make a claim for damages. It is important for shippers to carefully inspect their goods before shipment and ensure that they are properly packaged and secured to avoid any issues with the bill of lading.