Dan rank

system is a Japanese mark of level, which is used in traditional fine arts and martial arts. Originally invented in a Go school in the Edo period, this system was widely applied for martial arts and later introduced to other East Asian countries.In the modern Japanese martial arts, holders of dan ranks often wear a black belt. However, in certain martial arts such as iaidō, kendo or jōdō, no external signifier of rank is worn. Dan ranks are also given in arts such as the logical board games Go and Renju, the art of flower arrangement (ikebana), and tea ceremony.
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