Extension 
url 
value[x] Binding: ?? (required): One of the resource types defined as part of this version of FHIR.
Documentation for this formatThis is the set of resources that conform to either of the profiles Questionnaire Reference Resource (http://hl7.org/fhir/StructureDefinition/questionnaire-referenceResource) and Questionnaire Reference Resource (http://hl7.org/fhir/StructureDefinition/questionnaire-referenceResource). E.g. what you have to deal with if you get resources conforming to one of them
| Name | Flags | Card. | Type | Description & Constraints Filter: |
|---|---|---|---|---|
| Extension | 0..* | Allowed resource for reference | ||
| url | 1..1 | uri | identifies the meaning of the extension | |
| value[x] | 1..1 | code | Value of extension Binding: ?? (required): One of the resource types defined as part of this version of FHIR. | |
| Documentation for this format | ||||