The QDF file format: an electronic system to describe ancient andean   khipus
  With the goal of bringing to reseachers of the ancient andean khipus with a tool to share and process electronically the current corpus of these ancient information devices, I present on this paper a proposal for a Quipu Description Format (QDF), a XML based file format designed to describe such documents in a systematic and computer standard way. 
Manuel Arturo Izquierdo