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
The Canon of Judo mentioned. In the book, Kyuzo Mifune explains his metaphysical view of Judo, its role in Japanese society (and the world), and benefits to the individual player. He notes that Judo initially only included throws, and explains the difference between Judo and Ju-jutsu. He discusses the role of competition in Judo, and the purpose of free practice, randori, and explains that it is an indispensable part of the sport. Although the book mentions the five kata, it does not cover them. Furthermore, it does not cover Atemi-waza, but states that Atemi-waza include strikes, kicks, hits, and attacks using the fist, foot,