XPointer Question on Axes

The XPointer 1.0 specs specify the following extension
to XPath:
The production for NodeType now also includes 'point' 
and 'range'.

Does this imply that a queries (query fragments) like

   ancestor::point()

and

   self::range()

are correct, and if yes, what do they return,
if, for example, the context location is a
node location?

I have the feeling that I am constantly overlooking 
an essential phrase in the specs that explains all this.

--Mark Polman--