This is the ValueSet that contains all the codes in Document Class Value Set (http://hl7.org/fhir/ValueSet/document-classcodes) and IHE ClassCode_TEMP (http://medcomfhir.dk/ig/document/ValueSet/MedCom-ihe-core-classcode-VS-TEMP). E.g. what you have to deal with if you get resources containing codes in either of them