A quality common to all members of an object class. A property may be any feature that humans naturally use to distinguish one individual object from another. It is the human perception of a single quality of an object class in the real world. It is conceptual and thus has no particular associated means of representation by which the property can be communicated.

ObjectClass and Property are treated as a data model that can be mapped to like any other. This extension merely captures the Property element as a discrete code. The information conveyed here should also be conveyed in human-readable form in the mapping.map element.

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).