>From the introduction:
This is an XML DTD which describes a subset of HTML 4.0 for embedded
use within other XML DTDs. It is by intention equivalent
(within its scope) to -//W3C//DTD HTML 4.0 Transitional//EN, but is
not a derived work in the copyright sense. (Brief excerpts from
HTML 4.0 Transitional appear here and there.)
It is often convenient for XML documents to have a bit of
documentation somewhere in them. In the absence of a DTD like
this one, that documentation winds up being #PCDATA only, which is
a pity, because rich text adds measurably to the readability of
documents. By incorporating this DTD by reference (as an
external parameter entity) into another DTD, that DTD inherits
the capabilities of this one. Using HTML-compatible elements
and attributes allows the documentation to be passed straight
through to HTML renderers.
Current HTML renderers can cope with most XML tags, but empty
tags require special treatment. Inserting a space before the
terminating "/>" usually makes the "/" (which is not HTML)
invisible. Using "<TAG></TAG>" is not as effective, as the
latter is often misinterpreted as a second "<TAG>".
Note that since the elements of this DTD are intended to be
used within domain-specific elements of the surrounding DTD,
there is no "root element" corresponding to the HTML
element in HTML. Recommended content models for elements
containing documentation are "%horiz.model;" for simple
text fragments, and "%struct.model;" for documents in extenso.
-- John Cowan http://www.ccil.org/~cowan cowan@ccil.org You tollerday donsk? N. You tolkatiff scowegian? Nn. You spigotty anglease? Nnn. You phonio saxo? Nnnn. Clear all so! 'Tis a Jute.... (Finnegans Wake 16.5)