This is the CodeSystem that contains all the codes in Extension Style Codes (http://hl7.org/fhir/tools/CodeSystem/extension-style) and Extension Style Codes (http://hl7.org/fhir/tools/CodeSystem/extension-style). E.g. what you have to deal with if you get resources containing codes in either of them
Generated Narrative: CodeSystem 1a568dbd-29cd-40b3-8b4f-a4416cf0b21e-20
This code system http://hl7.org/fhir/comparison/CodeSystem/1a568dbd-29cd-40b3-8b4f-a4416cf0b21e-20 defines codes, but no codes are represented here