Extension: reference - FHIR v3.3.0

R4 Ballot #1 (Mixed Normative/Trial use)

This page is part of the FHIR Specification (v3.3.0: R4 Ballot 2). The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions . Page versions: R4B R4 R3 R2

Extension reference - Detailed Descriptions

Vocabulary Work Group

Maturity Level: 1

Informative

Use Context: Any

Detailed Descriptions for the elements in the extension.

Extension
Element Id	Extension
Definition	A logical reference (e.g. a reference to ValueSet.url) that identifies the value set/version that identifies the set of possible coded values this coding was chosen from or constrained by.
Control	0..1 This element is affected by the following invariants: ele-1
Invariants	Defined on this element ele-1: All FHIR elements must have a @value or children (xpath: @value\|f:\|h:div) ext-1: Must have either extensions or value[x], not both (xpath: exists(f:extension)!=exists(f:[starts-with(local-name(.), 'value')]))
Extension.id
Element Id	Extension.id
Definition	Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Control	0..1
Type	string
Extension.extension
Element Id	Extension.extension
Definition	An Extension
Control	0..0
Type	Extension
Slicing	This element introduces a set of slices. The slicing rules are: unordered Open discriminators: value:url
Extension.url
Element Id	Extension.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Control	1..1
Type	uri
Comments	The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.
Fixed Value	http://hl7.org/fhir/StructureDefinition/valueset-reference
Extension.valueUri
Element Id	Extension.valueUri
Definition	Value of extension - may be a resource or one of a constrained set of the data types (see Extensibility in the spec for list).
Control	0..1
Type	uri