This is the CodeSystem that contains all the codes in AdverseEventCategory (http://terminology.hl7.org/CodeSystem/adverse-event-category) and AdverseEventCategory (http://terminology.hl7.org/CodeSystem/adverse-event-category). E.g. what you have to deal with if you get resources containing codes in either of them
Generated Narrative: CodeSystem 9374b3b2-0331-4262-a17e-227b06a8f8f3-566
This code system http://hl7.org/fhir/comparison/CodeSystem/9374b3b2-0331-4262-a17e-227b06a8f8f3-566 defines codes, but no codes are represented here