Dan (rank) is by far the most recognizable symbol to the general public. The highest dan ranks are sometimes reserved for the founder or leaders of a style and only high-ranking students can be promoted to them. For example, only five living people hold a tenth dan in judo and only about thirty-five worldwide have been promoted to the rank since its inception; of those 10th dan promotions only fifteen were conferred by the Kodokan, all of them to Japanese judoka. This has led to upper level ranks becoming extinct in some arts. In other styles, the dan ranks are not the
Judo and Dong-Sik Yoon. Kano Jigoro's Kodokan judo is the most popular and well-known style of judo, but is not the only one. The terms judo and jujutsu were quite interchangeable in the early years, so some of these forms of judo are still known as jujutsu or jiu-jitsu either for that reason, or simply to differentiate them from mainstream judo. From Kano's original style of judo, several related forms have evolved—some now widely considered to be distinct arts: Kano's vision for judo was one of a martial way that could be practiced realistically. Randori (free practice) was a central part