[2] The systematic use of belt colour to denote rank was first used in Japan by Jigoro Kano, the founder of judo in the 1880s.

Previously, Japanese Koryu instructors tended to provide rank certificates only.

Testing for black belt is commonly more rigorous and more centralised than for lower grades.

As a "black belt" is commonly viewed as conferring some status, achieving one has been used as a marketing gimmick.

In others, a black belt student should not be called sensei until they are Sandan (third-degree black belt), or the titles kyosa or sabom in Korean martial arts as a second degree or higher, as this denotes a greater degree of experience and a sensei must have this and grasp of what is involved in teaching a martial art.