This is the CodeSystem that contains all the codes in Substance Category Codes (http://terminology.hl7.org/CodeSystem/substance-category) and Substance Category Codes (http://terminology.hl7.org/CodeSystem/substance-category). E.g. what you have to deal with if you get resources containing codes in either of them
Generated Narrative: CodeSystem 8d5e97a5-7160-4288-b89a-aac9d8740552-1616
This code system http://hl7.org/fhir/comparison/CodeSystem/8d5e97a5-7160-4288-b89a-aac9d8740552-1616 defines codes, but no codes are represented here