Dan (rank) highest level that might be attained, with instructor certification and judge/judgment authorization being understood as higher-level or more sophisticated. Many arts use between one and ten dan ranks: In some martial arts, black belts are worn for all "dan" grades. In others, the highest grade (10th "dan") wears a red colored belt. In Jūdo and Shotokan 6th to 8th "dan" may wear a red and white-patterned belt and 9th to 10th "dan" may wear a solid red belt. There is some variation even within styles. Generally, belts do not have markings that indicate the actual "dan" grade. Okinawan styles used
World Judo Championships except Oceania and Antarctica. The World Judo Championships team competition began in 1994. women's competition began in 1997, and after 1998 it was held once every four years until 2006. The competition will be held every year from 2007. Judoka who participate in the individual world championships often do not participate in the team competition. World Judo Championships The World Judo Championships are the highest level of international judo competition, along with the Olympic judo competition. The championships are held once every year (except the years when the Olympics take place) by the International Judo Federation, and qualified judoka compete