5.6 Retired Athletes Returning to Competition   5.6.1 If an International-Level Athlete or National-Level Athlete in WBSC’s Registered Testing Pool retires and then wishes to return to active participation in sport, the Athlete shall not compete in International Events or National Events until the Athlete has made himself or herself available for Testing, by giving six (6) months prior written notice to WBSC and their National Anti-Doping Organization.