This is the CodeSystem that contains all the codes in expansion parameter source code system (http://hl7.org/fhir/expansion-parameter-source) and expansion parameter source code system (http://hl7.org/fhir/expansion-parameter-source). E.g. what you have to deal with if you get resources containing codes in either of them
Generated Narrative: CodeSystem b39dc6a9-d6d1-4173-bc09-aee9a7d0f048-29
This code system http://hl7.org/fhir/comparison/CodeSystem/b39dc6a9-d6d1-4173-bc09-aee9a7d0f048-29 defines codes, but no codes are represented here