description: This cross-version extension represents ImmunizationRecommendation.recommendation.protocol.extension from http://hl7.org/fhir/StructureDefinition/ImmunizationRecommendation|1.0.2 for use in FHIR R4. package_name: hl7.fhir.uv.xver-r2.r4 derivation: constraint name: ext_R2_IR_re_pr_extension type: Extension elements: url: pattern: {type: uri, value: 'http://hl7.org/fhir/1.0/StructureDefinition/extension-ImmunizationRecommendation.recommendation.protocol.extension'} type: uri index: 0 package_version: 0.0.1-snapshot-1 class: extension kind: complex-type url: http://hl7.org/fhir/1.0/StructureDefinition/extension-ImmunizationRecommendation.recommendation.protocol.extension base: http://hl7.org/fhir/StructureDefinition/Extension version: 0.0.1-snapshot-1 required: [url]