WT 2021 Anti-Doping Rules  12  constitute a def ense to an anti -doping rule violation;15 provided, however, if the Athlete  or other Person  establishes that a departure from one  of the specific International Standard  provisions listed below could reasonably have caused an anti-doping rule violation based  on an Adverse Analytical Finding  or whereabouts failure, then WT shall have the burden to establish that such departure did not cause the Adverse Analytical Finding or the whereabouts failure:   (i)  a departure from the International Standard  for Testing  and Investigations related to Sample  collection or Sample  handling which could reasonably have caused an anti -doping rule violation based on an Adverse Analytical Finding , in which case WT shall have the burden to establish that such departure did not cause the Adverse Analytical Finding ;  (ii)  a departure from the International Standard  for Results Management  or International Standard  for Testing  and Investigations related to an Adverse Passport Finding  which could reasonably have caused an anti-doping rule violation, in which case WT shall have the burden to establish that such departure did not cause the anti -doping rule violation;   (iii)  a departure from the International Standard  for Results Manage ment  related to the requirement to provide notice to the Athlete  of the B Sample  opening which could reasonably have caused an anti -doping rule violation based on an Adverse Analytical Finding , in which case WT shall have the burden to establish that such departure did not cause the Adverse Analytical Finding ;16  (iv) a departure from the International Standard  for Results Management  related to Athlete  notification which could reasonably have caused an anti-doping rule violation based on a whereabouts failure, in which case WT shall have the burden to establish that such departure did not cause the whereabouts failure.