FHIR Release 3 (STU) R4 Ballot #1 (Mixed Normative/Trial use)

This page is part of the FHIR Specification (v3.0.2: STU 3). (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: R5 R4B R4 R3 R2

2.5.3 Extension - Detailed Descriptions

FHIR Infrastructure Work Group Maturity Level : 5 Ballot Status : Trial Use Normative

Normative Candidate Note: This page is candidate normative content for R4 in the Infrastructure Package . Once normative, it will lose it's Maturity Level, and breaking changes will no longer be made.

Extension
Standards Status This element has a standards status of "Normative" which is different to the status of the whole resource
Definition

Optional Extension Element - found in all resources.

Control 1..1
Requirements

The ability to add extensions in a structured way is what keeps FHIR resources simple.

Invariants Defined on this element
ext-1 : Must have either extensions or value[x], not both ( expression : extension.exists() != value.exists(), xpath: exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')]))
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.

Extension.value[x]
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 *
[x] Note See Choice of Data Types for further information about how to use [x]