Sets or retrieves the Uniform Resource Name (URN) of the object.
HRESULT value = object.put_urn(BSTR v);HRESULT value = object.get_urn(BSTR* p);
the URN. The value can be NULL.
A URN is an adjunct to a URL. A URL usually specifies an address of a resource on the Internet, whereas a URN specifies the identity of a resource, rather than its location.