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
Judo in the United States the naval academy. Judo suddenly had its first strong roots in the United States. Yoshiaki decided to return to Japan, but other Japanese Judo participants followed his example. The judo concentration was mainly centered in Washington before World War II, but several centers existed on the west coast, including Tokugoro Ito's dojo in Los Angeles, which was founded in 1910. Judo first entered the Western United States when Dr. T Ito began teaching Judo in Denver in the 1930s. During World War II Judo was banned in many areas due to the Japanese fear; however, a boom followed the war.