This is the CodeSystem that contains all the codes in US Core Category (http://hl7.org/fhir/us/core/CodeSystem/us-core-category) and US Core Category (http://hl7.org/fhir/us/core/CodeSystem/us-core-category). E.g. what you have to deal with if you get resources containing codes in either of them
Generated Narrative: CodeSystem f91b3000-4315-43c3-93e7-6119dfffb6fd-8
This code system http://hl7.org/fhir/comparison/CodeSystem/f91b3000-4315-43c3-93e7-6119dfffb6fd-8 defines codes, but no codes are represented here