This is the ValueSet that contains all the codes in eHDSI Observation Interpretation (http://terminology.ehdsi.eu/ValueSet/eHDSIObservationInterpretation) and eHDSI Observation Interpretation (http://terminology.ehdsi.eu/ValueSet/eHDSIObservationInterpretation). E.g. what you have to deal with if you get resources containing codes in either of them