This is the CodeSystem that contains all the codes in Citation Classification Type (http://terminology.hl7.org/CodeSystem/citation-classification-type) and Citation Classification Type (http://terminology.hl7.org/CodeSystem/citation-classification-type). E.g. what you have to deal with if you get resources containing codes in either of them
Generated Narrative: CodeSystem 0dec4686-57e5-4818-b054-7867bc94809d-155
This code system http://hl7.org/fhir/comparison/CodeSystem/0dec4686-57e5-4818-b054-7867bc94809d-155 defines codes, but no codes are represented here