This is the CodeSystem that contains codes in both PSS-QSI procedure codes (https://www.ehealth.fgov.be/standards/fhir/pss/CodeSystem/PSSQSIProcedures) and PSS-QSI procedure codes (https://www.ehealth.fgov.be/standards/fhir/pss/CodeSystem/PSSQSIProcedures).