This code system https://www.ehealth.fgov.be/standards/fhir/CodeSystem/be-cs-patientwill-category defines the following codes:

Code	Display	Definition
advanced-care-directive	Advanced Care Directive	General directives expressed voluntarily by the patient
research	Research	Consent to participate in research protocols and / or share results
treatment	Treatment	Specific treatments in the context of resuscitation and / or during hospitalization

Additional Language Displays

Code	French (Belgium) (fr)	Nederlands (België) (Dutch (Belgium), nl)
advanced-care-directive	Volontés diverses	Verschillende wensen
research	Recherche	Onderzoek
treatment	Traitement	Behandeling