Extension: reference - FHIR v3.0.2

FHIR Release 3 (STU)

This page is part of the FHIR Specification (v3.0.2: STU 3). The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions

Extension reference - Detailed Descriptions

Detailed Descriptions for the elements in the extension.

Extension
Definition	A logical reference (e.g. a reference to CodeSystem.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
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
Definition	May be used to represent additional information that is not part of the basic definition of the element. In order to make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.
Control	0..*
Type	Extension
Alternate Names	extensions, user content
Comments	There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
Slicing	This element introduces a set of slices. The slicing rules are: unordered Open discriminators: value:url
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/codesystem-reference
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