This is the CodeSystem that contains all the codes in Id Expectation Codes (http://hl7.org/fhir/tools/CodeSystem/id-expectation) and Id Expectation Codes (http://hl7.org/fhir/tools/CodeSystem/id-expectation). E.g. what you have to deal with if you get resources containing codes in either of them
Generated Narrative: CodeSystem ecfff9c0-d177-45a4-8b28-c899fac8813b-23
This code system http://hl7.org/fhir/comparison/CodeSystem/ecfff9c0-d177-45a4-8b28-c899fac8813b-23 defines codes, but no codes are represented here