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