Practically every martial art style began with one person’s ideas. That person developed followers and the art either flourished or it died. Whether it lived or died, was as much a result of its marketing was it a result of its effectiveness as a martial art. Bruce Lee had no controlling organization over JKD. Now there are differing masters who claim linage and to be teaching true JKD. The ITF had a single organization controlled by General Hi. Now that he is dead, there are at least three ITF organizations, each claiming to be the official organization. Most martial arts and martial art organizations are self-serving dynasties. As I have stated in TKDTutor.com, if you have a martial art instructor that satisfies all your needs, then you do not need anything else. Within that instructor’s martial art, school, or organization, you have rank that is accepted by other members and you receive certain privileges within the school or organization according to that rank. If you are happy with the situation, that is all you need! However, this does not mean that another instructor, school, or organization will recognize your rank or accept the philosophy, concepts, beliefs, etc. espoused by your martial art or instructor.
Credentials are testimonials to the validity of something, usually in the form of some written accreditation. In the martial arts, there are no legal requirements for any type of accreditation; therefore, anyone may claim to be anything they want to claim. A person’s marital art credentials may be anything: real, fraudulent, or imaginary. A black belt’s martial art background and linage, character, personality, integrity, education, personal philosophy, physical skills, competitive experience, teaching abilities, likability, etc. all add to or subtract from his or her creditability, but the person’s credentials are accreditations of these things from person’s or groups that are widely accepted as being legitimate sources for such accreditations. If ones instructor or organization meets all ones needs, that is all the credentials one requires. Just do not expect other to accept that accreditation.