This is the ValueSet that contains all the codes in Chemical Structure Data File Type Terminology (http://hl7.org/fhir/us/pq-cmc-fda/ValueSet/pqcmc-chemical-structure-datafile-type-terminology) and Chemical Structure Data File Type Terminology (http://hl7.org/fhir/us/pq-cmc-fda/ValueSet/pqcmc-chemical-structure-datafile-type-terminology). E.g. what you have to deal with if you get resources containing codes in either of them