The base URL for the server to which questionnaire response associated with this questionnaire should be submitted.

Indicates that the form has been designed with an expectation that it will be submitted to the specified URI. If multiple endpoints are specified, expectation is that answers are submitted to all endpoints.

If no end-point is specified, then the form is not exclusively designed to be submitted to a specific site. If and where the form needs to be submitted or how the form should be internally processed must be inferred from external context or system business rules.

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).