http://hl7.org/fhir/StructureDefinition/_datatype|5.2.0
Used when the actual type is not allowed by the definition of the element. In general, this should only arise when wrangling between versions using cross-version extensions - see [Cross Version Extensions](versions.html#extensions).
description: Used when the actual type is not allowed by the definition of the element. In general, this should only arise when wrangling between versions using cross-version extensions - see [Cross Version Extensions](versions.html#extensions). derivation: constraint name: Datatype type: Extension elements: extension: {index: 0} url: pattern: {type: Uri, value: 'http://hl7.org/fhir/StructureDefinition/_datatype'} index: 1 value: choices: [] index: 3 extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/StructureDefinition/_datatype base: http://hl7.org/fhir/StructureDefinition/Extension version: 5.2.0 required: [value]