This is the CodeSystem that contains all the codes in MeasureDataUsage (http://terminology.hl7.org/CodeSystem/measure-data-usage) and MeasureDataUsage (http://terminology.hl7.org/CodeSystem/measure-data-usage). E.g. what you have to deal with if you get resources containing codes in either of them
Generated Narrative: CodeSystem 63461cdc-5d1b-4619-930e-2c74c910a25f-539
This code system http://hl7.org/fhir/comparison/CodeSystem/63461cdc-5d1b-4619-930e-2c74c910a25f-539 defines codes, but no codes are represented here