This map was created to show the descent of the Zen ancestors, starting with Bodhidharma, and going down through the traditional five schools. The index not only allows locating a particular ancestor on the map, but also indicates where they can be found in the Blue Cliff Record, the Book of Serenity, and the Wumenguan (Mumonkan). Each ancestor is shown with their names in the Wade-Giles, Pinyin, and Romaji forms, along with their dates of birth and death (where known).