The total number of dan ranks is style-specific (1st through 5th and 1st through 10th are common in Japanese martial arts). The lower dan grades can normally be attained through a grading examination or sometimes through competition. The higher dan grades usually require years of experience and contribution to the relevant modern martial art. This may be through instruction or research and publication. These grades can only be awarded by a higher-graded representative of the principal dojo or sometimes by a steering committee. There is no set achievement level that is universal. Ranking systems are specific to the school or style, so ranks do not necessarily translate across different martial arts styles. In fact, dan ranks do not necessarily indicate one wears a black belt. In martial arts such as iaidō, kendō or jōdō, no external signifier of rank is worn, though a black belt is by far the most recognizable symbol to the general public.