I am lead to belive that the 'html.dtd' document type definition for
files according to the SGML standard has been successfully processed
by a commercial SGML package (SoftQuad Author/Editor). I'd encourage
people to try out other SGML systems (if necessary by posting stuff
to comp.text.sgml) and verify that we have the bugs shaken out, then
approach IANA with the spec.
--Ed