description: For items of type reference, the reference can be populated either by picking an existing entity or by creating a new one.  In the latter case, this Questionnaire allows specifying the Questionnaire to use in creating the target instance.  Typically this will result in a QuestionnaireResponse that can be [extracted](extraction.html) to produce the desired resource.  However, if the target resource for the reference is a QuestionnaireResponse, then the QuestionnaireResponse resulting from the Questionnaire can be referenced directly.
package_name: hl7.fhir.uv.sdc
derivation: constraint
name: LookupQuestionnaireExtension
type: Extension
elements:
  extension: {index: 0}
  url:
    pattern: {type: Uri, value: 'http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-lookupQuestionnaire'}
    index: 1
  value:
    choices: [valueCanonical]
    index: 3
  valueCanonical: {type: canonical, choiceOf: value, index: 4}
package_version: 4.0.0-ballot
extensions: {}
class: extension
kind: complex-type
url: http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-lookupQuestionnaire
base: http://hl7.org/fhir/StructureDefinition/Extension
version: 4.0.0-ballot