This is the ValueSet that contains all the codes in MDC Metric nomenclature (http://hl7.org/fhir/uv/pocd/ValueSet/11073MDC-metric) and MDC Metric nomenclature (http://hl7.org/fhir/uv/pocd/ValueSet/11073MDC-metric). E.g. what you have to deal with if you get resources containing codes in either of them