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 3b601e7f-3af7-485d-808e-d0591c910aa6-554
This code system http://hl7.org/fhir/comparison/CodeSystem/3b601e7f-3af7-485d-808e-d0591c910aa6-554 defines codes, but no codes are represented here