This is the ValueSet that contains all the codes in BeAllergyIntoleranceCode (https://www.ehealth.fgov.be/standards/fhir/allergy/ValueSet/be-allergyintolerancecode) and BeAllergyIntoleranceCode (https://www.ehealth.fgov.be/standards/fhir/allergy/ValueSet/be-allergyintolerancecode). E.g. what you have to deal with if you get resources containing codes in either of them