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/a5f384d8-a316-4736-ae90-ae021409e6cf-3432 defines codes, but no codes are represented here