This is the ValueSet that contains all the codes in eHDSI Absent Or Unknown Allergy (https://ncez.mzcr.cz/terminology/ValueSet/eHDSIAbsentOrUnknownAllergy-cz) and eHDSI Absent Or Unknown Allergy (https://ncez.mzcr.cz/terminology/ValueSet/eHDSIAbsentOrUnknownAllergy-cz). E.g. what you have to deal with if you get resources containing codes in either of them