description: This Extension contains a tracking number, such as a case number or file number assigned by an MDI information management system or EDRS, and can represent other tracking numbers, if required. package_name: hl7.fhir.us.mdi derivation: constraint name: ExtensionTrackingNumber type: Extension elements: extension: {index: 0} url: pattern: {type: Uri, value: 'http://hl7.org/fhir/us/mdi/StructureDefinition/Extension-tracking-number'} mustSupport: true index: 1 value: mustSupport: true choices: [valueIdentifier] index: 3 valueIdentifier: {type: Identifier, mustSupport: true, choiceOf: value, index: 4} value[x]: elements: type: short: Tracking Number Type (extensible value set) binding: {strength: extensible, valueSet: 'http://hl7.org/fhir/us/mdi/ValueSet/ValueSet-tracking-number-type'} mustSupport: true index: 5 system: {mustSupport: true, index: 6} value: {mustSupport: true, index: 7} package_version: 2.0.0-snapshot1 extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/us/mdi/StructureDefinition/Extension-tracking-number base: http://hl7.org/fhir/StructureDefinition/Extension version: 2.0.0-snapshot1