This is the ValueSet that contains all the codes in Reaction Manifestation Code (https://www.ehealth.fgov.be/standards/fhir/core-clinical/ValueSet/be-vs-reaction-manifestation-code) and Reaction Manifestation Code (https://www.ehealth.fgov.be/standards/fhir/core-clinical/ValueSet/be-vs-reaction-manifestation-code). E.g. what you have to deal with if you get resources containing codes in either of them