This is the ValueSet that contains all the codes in IVR valueset mission Emergency doctor system (.143.11.12) (http://fhir.ch/ig/ch-ems/ValueSet/IVR-VS-emergDoctSystem) and IVR Emergency Doctor System (http://fhir.ch/ig/ch-ems/ValueSet/IVR-VS-emergDoctSystem). E.g. what you have to deal with if you get resources containing codes in either of them