The status of the response. If the evaluation is completed successfully, the status will indicate success. However, in order to complete the evaluation, the engine may require more information. In this case, the status will be data-required, and the response will contain a description of the additional required information. If the evaluation completed successfully, but the engine determines that a potentially more accurate response could be provided if more data was available, the status will be data-requested, and the response will contain a description of the additional requested information.

unique id for the element within a resource (for internal references).

An Extension

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 should be version specific. This will ideally be the URI for the Resource Profile defining the extension, with the code for the extension after a #.

Value of extension - may be a resource or one of a constrained set of the data types (see Extensibility in the spec for list).