|FHIR Infrastructure Work Group||Maturity Level : Normative||Standards Status : Normative|
|Standards Status||This element has a standards status of "Normative"|
Optional Extension Element - found in all resources.
The ability to add extensions in a structured way is what keeps FHIR resources simple.
Source of the definition for the extension code - a logical name or a URL.
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.
Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
|[x] Note||See Choice of Data Types for further information about how to use [x]|