Self-identified Indigenous identity answers offered by Nexus EMR — an enumerated mirror of Canada Health Infoway's IndigenousIdentityCode ValueSet, source version 1.3.0 (published 2026-02-28, on behalf of CIHI; canonical https://fhir.infoway-inforoute.ca/ValueSet/indigenousidentitycode). The absence concepts (Asked But Declined, Do not know, Not applicable) are first-class members per the source composition — captured answers, not missing data.