67  [Comment to Article 13.3: Given the different circumstances of each anti-doping rule violation investigation and Results Management process, it is not feasible to establish a fixed time period for IRF to render a decision before WADA may intervene   IRF 2021 Anti-Doping Rules Page 48 of 68     13.4 Appeals Relating to TUEs  TUE decisions may be appealed exclusively as provided in Article 4.4.