description: This cross-version extension represents Signature.who[x] from http://hl7.org/fhir/StructureDefinition/Signature|1.0.2 for use in FHIR R4. package_name: rs/hl7.fhir.uv.xver derivation: constraint name: ext_R2_Signature_who type: Extension elements: value: base: {path: 'Extension.value[x]'} short: Who signed the signature choices: [valueUri, valueReference] index: 1 valueUri: base: {path: 'Extension.value[x]'} type: uri short: Who signed the signature choiceOf: value index: 2 valueReference: short: Who signed the signature refers: ['http://hl7.org/fhir/StructureDefinition/Device', 'http://hl7.org/fhir/StructureDefinition/Organization', 'http://hl7.org/fhir/StructureDefinition/Patient', 'http://hl7.org/fhir/StructureDefinition/Practitioner', 'http://hl7.org/fhir/StructureDefinition/RelatedPerson'] type: Reference base: {path: 'Extension.value[x]'} choiceOf: value index: 3 url: pattern: {type: uri, value: 'http://hl7.org/fhir/1.0/StructureDefinition/extension-Signature.who'} type: uri index: 4 package_version: r2.r4-0.0.1-snapshot-1 class: extension kind: complex-type url: http://hl7.org/fhir/1.0/StructureDefinition/extension-Signature.who base: http://hl7.org/fhir/StructureDefinition/Extension version: 0.0.1-snapshot-1 required: [url]