Current Build
FHIR Infrastructure Work GroupMaturity Level: 5Ballot Status: Trial Use
Extension
Definition

Optional Extension Element - found in all resources.

Control1..1
Requirements

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

InvariantsDefined 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.

Control1..1
Typeuri
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).

Control0..1
Type*
[x] NoteSee Choice of Data Types for further information about how to use [x]