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Re: ERB meeting, 30 October 1996

From: Michael Sperberg-McQueen <U35395@UICVM.UIC.EDU>
Date: Wed, 30 Oct 96 17:03:58 CST
Message-Id: <199610302330.SAA24455@www10.w3.org>
To: W3C SGML Working Group <w3c-sgml-wg@w3.org>
On Wed, 30 Oct 1996 14:59:04 -0500 I said:
> ...
>Agreed unanimously:
> ...
>  - to use the string '/>' as the NET delimiter in the SGML
>    declaration of XML documents

But I forgot to add the important constraint that in XML the
delimiter '/>' is explicitly a tag-close delimiter for empty
elements, and may not be used to end start-tags for non-empty
elements, or as a null end-tag (NET), as described in 8879, clauses
7.4.1.3 and 7.5.1.3.  This constraint is essential in order to
ensure that empty elements, and *only* empty elements, have
tags of the form <e/>.

The identification of '/>' with the NET delimiter is exclusively a
technique to allow Full-SGML systems to read XML documents.  XML does
not use any form of minimized start- or end-tags (ERB decision on
question A.4, announced by Tim Bray on 9 October) and thus has, in
effect, no NET delimiter.

Current Full-SGML systems will not typically have an option to allow
the user to request that elements declared EMPTY and elements with a
CONREF attribute for which a value is specified, and only such
elements, be written out using the form <e/>.  We may hope that this
will change.  In the meantime, the form <e> is legal, as long as the
empty elements are declared as such.

-CMSMcQ
Received on Wednesday, 30 October 1996 18:30:33 EST

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