The right to retain the lawful possession of the property of another until the owner fulfills a legal duty to the person holding the property, such as the payment of lawful charges for work done on the property. A mortgage is a common lien. Liens may arise in three ways: 1. Expressed contract; 2. Implied contract, as from general or particular usage of trade (Property, Inventory, Accounts Receivables) 3. Legal relation between the parties, which may be created in three ways. i. When the law casts an obligation on a party to do a particular act and in return for which, to secure him payment, it gives him such lien; common carriers and inn keepers are among this number; ii When goods are delivered to a tradesman or any other, to expend his labor upon, he is entitled to detain those goods until he is remunerated for the labor which he so expends; iii When goods have been saved from the perils of the sea, the salvor may detain them until his claim for salvage is satisfied; but in no other case has the finder of goods a lien.