IBM-DM-003: Unparsed entities

Data Model Section 3.2 (Construction from an Infoset): First bullet states 
that general and external parsed entities must be fully expanded, and the 
Infoset must not contain any unexpanded entity reference info items. This 
leaves open the question about unparsed entities. Can an Infoset contain 
unexpanded references to unparsed entities? If so, how are they 
represented in the data model? If not, the what is the use of the unparsed 
entity accessors of the document node?