Re: Simple(?) question on obscure comments detail

Foteos Macrides (MACRIDES@SCI.WFBR.EDU)
Mon, 23 Sep 1996 12:53:21 -0500 (EST)


Date: Mon, 23 Sep 1996 12:53:21 -0500 (EST)
From: Foteos Macrides <MACRIDES@SCI.WFBR.EDU>
Subject: Re: Simple(?) question on obscure comments detail
To: murray@spyglass.com
Cc: www-html@w3.org
Message-id: <01I9TH5EIK2Q0077FL@SCI.WFBR.EDU>

murray@spyglass.com (Murray Altheim) wrote:
>[...]
>You may find both comment and DOCTYPE declarations in an HTML _file_, but
>the structure of an HTML _document_ includes both the prologue and document
>instance, so the DOCTYPE is considered part of the prologue. This is one of
>the interesting parts of SGML: you preface your content with the
>specification of its markup structure.
>
>You could theoretically include the entire DTD in the prologue, rather than
>just referencing it as a piece of PUBLIC text. You can also include a
>modified SGML declaration, as is being done for the internationalized HTML
>DTD that handles the extended character set:
>
>     BASESET  "ISO Registration Number 176//CHARSET
>               ISO/IEC 10646-1:1993 UCS-2 with
>               implementation level 3//ESC 2/5 2/15 4/5"
>
>Current HTML-only browsers wouldn't understand modifications to the
>prologue (most ignore it entirely), but an SGML browser would.
>
>Prologue:
>     <!SGML  "ISO 8879:1986"   ...   >                  (assumed)
>     <!DOCTYPE html PUBLIC "-//IETF//DTD HTML//EN">
>
>Document instance (the "HTML element"):
>     <HTML>
>     [...]
>     </HTML>
>[...]

	OK, so to continue this lesson, how would the modular DTD
work, i.e., what would be the structure of an "HTML _file_" which
uses it, and can it internally avoid foul ups for currently
deployed (but not *too* old) browsers, or would providers *need*
to have two different versions of documents offered on the basis
of content negotiation?  If this requires too long an answer, put
off the question about content negotiation, for now, and hopefully
get across the basic concept of a modular DTD for plain folks. :) :)

				Fote

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