To belong to the tribe of white battle pyjamas of KU under Patrick McCarthy aka "Pate" aka the founder of Koryu Uchinadi-style, you'll also have to pay yearly the IRKRS-payment. (IRKRS = International Ryukyu Karate Research Society, as in Patrick McCarthy's international Koryu Uchinadi organisation). IRKRS-payment is voluntary but official Koryu Uchinadi-board has decided that for pursuing green or higher belts in KU, you will require an international membership. In other words, IRKRS-payment is mandatory for those who have a green or darker belt (including those orange belts who are aiming for a green belt graduation).