> DocBook has such a declaration in its DTD.  It
might seem strange, but it does have its uses.
We did have a recursive DOCBOOK element in earlier versions, but
it is gone from version 2.1.  We realized that it didn't fit with
the Set/Book/Chapter model of the rest of the DTD.  It *did* have
its uses, though, and it may be appropriate for the HTML element
to be recursive; we just don't have it in Docbook any more.
Also, what are your expectations for browser behavior when a
compound document is accessed?  Must all the pieces be retrieved
and assembled before any is rendered?
Regards,
-- Terry Allen (terry@ora.com) Editor, Digital Media Group O'Reilly & Associates, Inc. Sebastopol, Calif., 95472