description: This cross-version extension represents EvidenceVariable.characteristic.definition[x] from http://hl7.org/fhir/StructureDefinition/EvidenceVariable|4.3.0 for use in FHIR R4. package_name: hl7.fhir.uv.xver derivation: constraint name: Ext_R4B_EvidenceVariable_ch_definition type: Extension elements: url: base: {max: '1', min: 1, path: Extension.url} pattern: {type: Uri, value: 'http://hl7.org/fhir/4.3/StructureDefinition/extension-EvidenceVariable.characteristic.definition'} index: 0 value: base: {max: '1', min: 0, path: 'Extension.value[x]'} short: What code or expression defines members? choices: [valueReference, valueCanonical, valueCodeableConcept, valueExpression] index: 2 valueReference: base: {max: '1', min: 0, path: 'Extension.value[x]'} type: Reference short: What code or expression defines members? choiceOf: value index: 3 valueCanonical: base: {max: '1', min: 0, path: 'Extension.value[x]'} type: canonical short: What code or expression defines members? choiceOf: value index: 4 valueCodeableConcept: base: {max: '1', min: 0, path: 'Extension.value[x]'} type: CodeableConcept short: What code or expression defines members? choiceOf: value index: 5 valueExpression: base: {max: '1', min: 0, path: 'Extension.value[x]'} type: Expression short: What code or expression defines members? choiceOf: value index: 6 package_version: r4b.r4-0.0.1-snapshot-2 class: extension kind: complex-type url: http://hl7.org/fhir/4.3/StructureDefinition/extension-EvidenceVariable.characteristic.definition base: http://hl7.org/fhir/StructureDefinition/Extension|4.0.1 version: 0.0.1-snapshot-2 required: [url]