Welcome to the Patterns Forum.
Here you can ask any questions related to the Yoo-Sin, by starting a new topic or continuing an existing thread.
Posts may be answered by any member who can offer assistance. Verified members will have their grade and certificate number listed in their profile. Please be aware these replies represent the posting member and may or may not be in-line with the ITF policy. Definitive answers can only be given by the ITF Technical Committee and will as such be clearly identified.
facile est inventis addere.
it is easy to add to things already invented.