D.1 Distinguish partial and full DTDs?

On 30 October 1996, the ERB will vote to decide the following
question.  A straw poll indicates the question needs further
discussion in the work group.

D.1 What behavior should XML systems exhibit if no DTD, or only a
partial DTD, is given with a document?  In particular, should there
be a way to distinguish a document instance for which a DTD exists
but is not given from an instance for which no DTD exists?