When a Prohibited Substance or itsMarkers or Metabolites is detected in an Athlete’sSpecimen in violation of Article 2.1 (presence ofProhibited Substance ), the Athlete must alsoestablish how the Prohibited Substance entered hisor her system in order to have the period ofIneligibility reduced.Article 10.5 is meant to have animpact only in cases where thecircumstances are truly exceptionaland not in the vast majority of cases.