| Source Element | Usage | Target |
|---|---|---|
| Extension.id | UseElementSameName | Extension.id |
| Extension.extension | UseElementSameName | Extension.extension |
| Extension.url | UseElementSameName | Extension.url |
| Extension.value[x] | UseExtension | http://hl7.org/fhir/4.3/StructureDefinition/extension-Extension.value |