When you are ready to compete, you better hold a WTF approved Dan certificate issued by Kukkiwon Korea, otherwise, you can not compete in WTF...
Here it the official link to Kukkiwon English site (WTF only): http://www.kukkiwon.or.kr/english/index.jsp
Belt system in Korea (20 years ago, not sure how it goes these days): White, Yellow, Blue, Red, Red/Black (under 15 yrs old) or Black (15 yrs...
Separate names with a comma.