This is the ValueSet that contains all the codes in MDC Object and Device nomenclature (http://hl7.org/fhir/uv/phd/ValueSet/MDCobject) and MDC Object and Device nomenclature (http://hl7.org/fhir/uv/phd/ValueSet/MDCobject). E.g. what you have to deal with if you get resources containing codes in either of them