#3 preserving entities

[Oliver Becker]

Many XML authors use entity references within their
documents.
A transformation of such a document should preserve these
references. That means, the document type declaration
including
the internal subset has to be preserved, too.

A simple mechanism could use a simple flag that
controls the
handling of entity references. A more sophisticated
mechanism
would allow the processing of entity references and DTD
declarations
in an arbitrary way. This includes generating entity
declarations
and references.