"Each student is required to know and be able to recite each section of this manual from memory with few errors, answer any and all exam questions presented by his or her Sensei (teacher), and properly execute all techniques to the satisfaction of his or her Sensei and Sempai (senior students) to receive an Kyu ranking (1st – 5th). The 5 Kyus or grades, are divided between 5 belt colors: white (5th kyu), blue (4th kyu), yellow (3rd kyu), green (2nd kyu), brown (1st kyu).
Each student must also be able teach the techniques, concepts, drills, safety principles, and guiding philosophy of this system in order to receive his or her 1st degree (1st dan) black belt and become a full instructor. A student is eligible for an instructor’s exam after completing two years as an active black belt under a qualified Sensei. All degrees beyond the 1st degree (1st dan) can only be awarded by the candidate satisfying all Kyu and 1st Dan requirements outlined above and taking an exam issued by a certified council of instructors in good standing.
Black belt (1st dan; “degree”) means you have mastered the basics. 3rd dan is the highest degree an instructor can achieve in this system through examination and testing. Any dan grades beyond 3rd are honorary, based upon ones dedication to this art/science, as well as helping others."
From "Shigaisen: Official Manual of the GCL Method of Modern Karate: The Way of Real Fighting Karate As I Understand It". by Sensei Gregory C. Lewis.