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/0229f20e-bdf6-4558-8625-5d09cf27fb48-3432
defines codes, but no codes are represented here