In common law, a deed (anciently "an evidence") is any legal instrument in writing which passes, affirms or confirms an interest, right, or property and that is signed, attested, delivered, and in some jurisdictions, sealed. It is commonly associated with transferring (conveyancing) title to property. The deed has a greater presumption of validity and is less rebuttable than an instrument signed by the party to the deed. A deed can be unilateral or bilateral. Deeds include conveyances, commissions, licenses, patents, diplomas, and conditionally powers of attorney if executed as deeds. The deed is the modern descendant of the medieval charter, and delivery is thought to symbolically replace the ancient ceremony of livery of seisin.