A chirograph (cyrograph) is the term given to a medieval document, which has been written in duplicate, 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. The cut itself would often be made to produce a wavy or serrated edge, in order to further reduce the scope for forgery, and this practice gave rise to the document description "indenture", since these edges would be said to be "indented".[1] The earliest surviving portion of a chirograph in England dates from the middle of the ninth century.[2]
A more restricted use of the term "chirograph" is to describe a papal decree whose circulation—unlike an encyclical—is limited to the Roman curia.[3]