description: A pattern that all the target resources follow - that is, a pattern that they all declare their relationship to. package_name: hl7.fhir.uv.extensions derivation: constraint name: Pattern type: Extension elements: extension: {index: 0} url: pattern: {type: Uri, value: 'http://hl7.org/fhir/StructureDefinition/elementdefinition-pattern'} index: 1 value: choices: [valueCanonical] index: 3 valueCanonical: {type: canonical, choiceOf: value, index: 4} package_version: 5.1.0-snapshot1 extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/StructureDefinition/elementdefinition-pattern base: http://hl7.org/fhir/StructureDefinition/Extension version: 5.1.0-snapshot1 required: [valueCanonical, value]