The FHIR CodeSystem Definition file contains the canonical CodeSystem Resource for defining LOINC as a CodeSystem in HL7 FHIR, release notes, and readme.
For more information on LOINC's FHIR terminology service, refer to https://loinc.org/fhir/. Use of LOINC is governed by the LOINC License: https://loinc.org/license/.