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 dbac6c5e-61a0-43cb-9ce7-01f3150b1311-698
This code system http://hl7.org/fhir/comparison/CodeSystem/dbac6c5e-61a0-43cb-9ce7-01f3150b1311-698 defines codes, but no codes are represented here