description: 'R4: `SubstanceSpecification.description` (new:string)' package_name: hl7.fhir.uv.xver-r4.r3 derivation: constraint name: ExtensionSubstanceSpecification_Description type: Extension elements: url: base: {max: '1', min: 1, path: Extension.url} pattern: {type: Uri, value: 'http://hl7.org/fhir/4.0/StructureDefinition/extension-SubstanceSpecification.description'} index: 0 value: base: {max: '1', min: 0, path: 'Extension.value[x]'} short: Textual description of the substance choices: [valueString] index: 2 valueString: short: Textual description of the substance type: string base: {max: '1', min: 0, path: 'Extension.value[x]'} choiceOf: value index: 3 package_version: 0.1.0 class: extension kind: complex-type url: http://hl7.org/fhir/4.0/StructureDefinition/extension-SubstanceSpecification.description base: http://hl7.org/fhir/StructureDefinition/Extension version: 0.1.0 required: [url]