description: This cross-version extension represents ResearchStudy.site from http://hl7.org/fhir/StructureDefinition/ResearchStudy|4.0.1 for use in FHIR R5. package_name: hl7.fhir.uv.xver-r4.r5 derivation: constraint name: ext_R4_ResearchStudy_site type: Extension elements: value: base: {path: 'Extension.value[x]'} short: Facility where study activities are conducted choices: [valueReference] index: 1 valueReference: short: Facility where study activities are conducted refers: ['http://hl7.org/fhir/StructureDefinition/Location'] type: Reference base: {path: 'Extension.value[x]'} choiceOf: value index: 2 url: pattern: {type: uri, value: 'http://hl7.org/fhir/4.0/StructureDefinition/extension-ResearchStudy.site'} type: uri index: 3 package_version: 0.0.1-snapshot-1 class: extension kind: complex-type url: http://hl7.org/fhir/4.0/StructureDefinition/extension-ResearchStudy.site base: http://hl7.org/fhir/StructureDefinition/Extension version: 0.0.1-snapshot-1 required: [url]