This decision may be appealed under Article 13.27  Any competitive results obtained in violation of this Article 5.6.1 shall be Disqualified  unless the Athlete  can establish that he or she could not have reasonably known that this was an International Event  or a National Event .5.6.2  If an Athlete  retires from sport while subject to a period of Ineligibility , the Athlete  must notify the Anti-Doping Organization  that imposed the period of Ineligibility  in writing of such retirement.