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/5b1132b8-51e9-46ac-8efa-9d1c907d9515-3348 defines codes, but no codes are represented here