This is the ValueSet that contains all the codes in XDS Class Codes (http://hl7.eu/fhir/imaging-r5/ValueSet/im-xds-class-code-valueset) and XDS Class Codes (http://hl7.eu/fhir/imaging-r5/ValueSet/im-xds-class-code-valueset). E.g. what you have to deal with if you get resources containing codes in either of them