World Anti-Doping Code • 201519 2.1.2   Sufficient pr oof of an anti-doping rule violation under Article 2.1 is established by any of the following: presence of a Prohibited Substance or its Metabolites or Markers in the athlete’s A Sample where the athlete waives analysis of the B Sample and the B Sample is not analyzed; or, where the athlete’s B Sample is analyzed and the analysis of the athlete’s B Sample confirms the presence of the Prohibited Substance or its Metabolites or Markers found in the athlete’s A Sample; or, where the athlete’s B Sample is split into two bottles and the analysis of the second bottle confirms the presence of the Prohibited Substance or its Metabolites or Markers found in the first bottle.