In the age of sail, cargo and ships became lost more often than today. This bill proved that cargo expenses were paid, but became mainly a proof that the cargo was really on board and thus become a negotiable property title. Under this type of carriage, the bill of lading assumes two main tasks, as cargo receipt and property title. In linear shipping It assumes a triple identity: property title, cargo receipt and carriage contract. In tramp shipping, object of this wiki entry, the carriage contract is the charter party