An article is “lost” when the owner has lost the possession or custody of it, involuntarily and by any means, but more particularly by accident or his own negligence or forgetfulness, and when he is ignorant of its whereabouts or cannot recover it by an ordinarily diligent search. Lost or not lost. A phrase sometimes inserted in policies of marine insurance to signify that the contract is meant to relate back to the beginning of a voyage now in progress, or to some other antecedent time, and to be valid and effectual even if, at the moment of executing the policy, the vessel should have already perished by some of the perils insured against, provided that neither party has knowledge of that fact or any advantage over the other in the way of superior means of information. Lost papers. Papers which have been so mislaid that they cannot be found after diligent search. Lost property. Property which the owner has involuntarily parted with and does not know where to find or recover it, not including property which he has intentionally concealed or deposited in a secret place for safe keeping.