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 9137e97b-aec1-4316-a65f-a273ef42c951-1496
This code system http://hl7.org/fhir/comparison/CodeSystem/9137e97b-aec1-4316-a65f-a273ef42c951-1496
defines codes, but no codes are represented here