Legal right or action against ‘the thing’ as opposed to the person (in personam). It includes a maritime lien that a salvor may have against the saved property (vessel or cargo). Admiralty law allows a salvor to arrest or seize property to enforce his legal right rather than arresting or seizing the owner, whose identity is often not known. The seized property is security until the claim is settled or until acceptable security is substituted. The salvor may relinquish his right to hold property and take up an action in personam for the value of the salvage award.