Identifiers - what is identified? When XML is used to represent a directed laballed graph which is used to represent information about things, then one must be able to make statements about parts of an XML document, parts of the DLG (such as RDF nodes) and of course the objects described. In most cases it seems obvious to the human reader. The jam jar label text does not (normally) read "jam jar label text" or "jam jar label" or "jam jar" but "jam". Take the case of a statement about a person...
