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