description: A reference to a CodeSystem or ValueSet that establishes the allowable values for a code system property package_name: hl7.fhir.us.ecr.r4b derivation: constraint name: USPublicHealthCodeSystemPropertyBindingExtension type: Extension elements: extension: {index: 0} url: pattern: {type: Uri, value: 'http://hl7.org/fhir/us/ecr/StructureDefinition/us-ph-codesystem-property-binding-extension'} index: 1 value: choices: [valueCanonical] index: 3 valueCanonical: {type: canonical, choiceOf: value, index: 4} package_version: 2.1.1 extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/us/ecr/StructureDefinition/us-ph-codesystem-property-binding-extension base: http://hl7.org/fhir/StructureDefinition/Extension version: 2.1.1 required: [valueCanonical, value]