A reference to an extensible value set specified in a parent profie in order to allow a conformance checking tool to validate that a code not in the extensible value set of the profile is not violating rules defined by parent profile bindings.

This extension is only needed where the binding strength is 'extensible', the parents are also 'extensible'. This allows a validator to work around the fact that restricting extensible value sets in child profiles loses constraints out of the parent profiles, (e.g. codes to be used when appropriate).

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

An Extension

• unordered
• Open
• discriminators: value:url

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).