Documents that cannot be located after a thorough, careful, and diligent search has been made for them.
In some jurisdictions, documents that have been stolen are held to be lost. An instrument that the owner has voluntarily and intentionally destroyed in order to cancel its legal effects is not a lost instrument, nor is an instrument that has been mutilated. Generally the loss of a written instrument does not affect the validity of the transaction that it represents, since a copy can usually be established in court. An action to restore a lost instrument is not one for relief against a wrong but rather one to enforce the plaintiff's interests. It can be initiated immediately subsequent to the loss, and all interested persons should be made parties to, and should be given notice of, such proceedings.
An action to establish a lost instrument indicating ownership of land, such as a deed, can be commenced by anyone who has an interest in the subject matter, such as an heir of a deceased property owner. This type of case is analogous to a Quiet Title Action.