This is the ValueSet that contains codes in both List of possible genders at birth in Belgium (https://www.ehealth.fgov.be/standards/fhir/core/ValueSet/be-vs-gender-at-birth) and BeVSGenderAtBirth (https://www.ehealth.fgov.be/standards/fhir/core/ValueSet/be-vs-gender-at-birth).