This is the ValueSet that contains all the codes in Representation Types (http://hl7.org/fhir/us/pq-cmc-fda/ValueSet/pqcmc-representation-types) and Representation Types (http://hl7.org/fhir/us/pq-cmc-fda/ValueSet/pqcmc-representation-types). E.g. what you have to deal with if you get resources containing codes in either of them