This is the ValueSet that contains all the codes in WHO ATC - IPS (http://hl7.org/fhir/uv/ips/ValueSet/whoatc-uv-ips) and WHO ATC - IPS (http://hl7.org/fhir/uv/ips/ValueSet/whoatc-uv-ips). E.g. what you have to deal with if you get resources containing codes in either of them