Chirograph

• abstract: A chirograph is a medieval document, which has been written in triplicate] or very occasionally [[quadruplicate on a single piece of parchment, where the Latin word "chirographum" (or equivalent) has been written across the middle, and then cut through. By this means both parties to an agreement could possess a copy of its written record, and each copy could be verified as genuine through introduction to, and comparison with, the other.

以上来源于: WordNet