Võ phục not necessarily adopted by all practitioners, as evidenced throughout 1973-1990 when many practitioners under a separate development of Vovinam, the "Viet Vo Dao Federation," wore black uniforms. By 1990, however, after further meetings between councils, indigo had been adopted by the majority of Vovinam practitioners in and outside of Vietnam. Deep blue/indigo (Vietnamese: Lam) is now the internationally accepted color of Vo Phuc for Vietnamese martial arts. The "võ phục" of Vovinam are very similar, if not nearly identical, to the "keikogi" of Japanese martial arts. Both top and bottom of the uniform are constructed in much the same way
Japanese martial arts rule of thumb, the primary purpose of a "koryū" martial art was for use in war. The most extreme example of a "koryū" school is one that preserves its traditional, and often ancient, martial practices even in the absence of continuing wars in which to test them. Other "koryū" schools may have made modifications to their practices that reflect the passage of time (which may or may not have resulted in the loss of ""koryū"" status in the eyes of its peers). This is as opposed to "modern" martial arts, whose primary focus is generally upon the self-improvement (mental, physical,