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Re: ELEMENT declaration in DTD
- To: docbook at lists dot oasis-open dot org
- Subject: Re: DOCBOOK: ELEMENT declaration in DTD
- From: Mike Sangrey <mike at sojurn dot lns dot pa dot us>
- Date: Tue, 06 Jun 2000 09:56:02 -0400
- Reply-To: docbook at lists dot oasis-open dot org
mike@sojurn.lns.pa.us said:
> Everywhere in the DocBook DTD files one sees lines like:
> <!ELEMENT foobar - - ((some|stuff)*)> or
> <!ELEMENT foobar - O ((some|stuff)*)>
> What are the '-' and 'O' doing in there? A case of virtual beer if
> you include an XML Spec. section citation. :-)
I've answered my own question. The '- -' and '- O' indicate
'Required'/'Optional' begin and end tags. And (this is where my confusion
lay), it is allowed in the more general SGML and _not_ in XML.
BTW, discovered this by looking at the source of a dtd2html PERL script. I
love Open Source. :-)
Thanks anyway.
--
Mike Sangrey
mike@sojurn.lns.pa.us
Landisburg, Pa.
There is no 'do' in faith, everywhere present within it is 'done'.