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