This is the CodeSystem that contains all the codes in AllergyIntoleranceCertainty (http://terminology.hl7.org/CodeSystem/reaction-event-certainty) and AllergyIntoleranceCertainty (http://terminology.hl7.org/CodeSystem/reaction-event-certainty). E.g. what you have to deal with if you get resources containing codes in either of them
Generated Narrative: CodeSystem ad63b62d-52f3-4c4a-8fee-31e713b8e7dc-716
This code system http://hl7.org/fhir/comparison/CodeSystem/ad63b62d-52f3-4c4a-8fee-31e713b8e7dc-716 defines codes, but no codes are represented here