No fixed rules for its formation exist, but the sangō is basically topographical in origin, as in Hieizan Enryaku-ji: these two names together mean Mount Hiei's Enryaku-ji. For this reason it is sometimes used as a personal name, particularly in Zen. There may be however some other semantic relationship between the sangō and the san'in-jigō, as for example in the case of Rurikōzan Yakushi-ji. The sangō and the jigō are simply different names of the same god. Sometimes the sangō and the jigō are both posthumous names, for example of the founder's mother and father.