Grade; rank. Used in the black belt grading system popularized by Jigoro KANO, founder of judo, which has been generally adopted in modern Japanese martial arts. After World War II, some classical martial schools also implemented the dan grading system, which at times coexists with the traditional grading method of granting transmission scrolls. The DAITO-RYU AIKI BUDO school of Tokimune TAKEDA is such an example. The dan system is also used in disciplines unrelated to the martial arts such as the game of go.