This is the CodeSystem that contains all the codes in expansion parameter source (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 3099ac23-0942-4450-b678-d1831a38da6f-29
This code system http://hl7.org/fhir/comparison/CodeSystem/3099ac23-0942-4450-b678-d1831a38da6f-29
defines codes, but no codes are represented here