This is the ValueSet that contains all the codes in Encounter Class Value Set (http://hl7.eu/fhir/hdr/ValueSet/hdr-encounterClass-eu-hdr) and Encounter Class Value Set (http://hl7.eu/fhir/hdr/ValueSet/hdr-encounterClass-eu-hdr). E.g. what you have to deal with if you get resources containing codes in either of them