This is the CodeSystem that contains all the codes in CommunicationCategory (http://terminology.hl7.org/CodeSystem/communication-category) and CommunicationCategory (http://terminology.hl7.org/CodeSystem/communication-category). 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-a273ef42c951-740
This code system http://hl7.org/fhir/comparison/CodeSystem/9137e97b-aec1-4316-a65f-a273ef42c951-740
defines codes, but no codes are represented here