This is the CodeSystem that contains codes in both WHO ATC (http://www.whocc.no/atc) and WHO ATC (http://www.whocc.no/atc).
This code system http://hl7.org/fhir/comparison/CodeSystem/9137e97b-aec1-4316-a65f-a273ef42c951-3432 defines codes, but no codes are represented here