Including entity definitions in the document declaration subset is
definitely ok as far as SGML goes. The question is to what extent we
*require* conformant 3.0 browser to support extensions to the DTD in this
way. For instance, should browsers be able to cope with marked sections?
What about <!ELEMENT> and <!ATTLIST>?
Personally, I feel we should require entity definitions, and would like
support for marked sections too, but feel that is far enough.
In the not very distant future, browsers will be expected to cope with fairly
arbitrary document type definitions, so we need to be flexible here.
-- Dave Raggett <email@example.com> tel: +44 272 228046 fax: +44 272 228003 Hewlett Packard Laboratories, Filton Road, Bristol BS12 6QZ, United Kingdom