> >In yesterday's Java Study Group I was talking about the importance of
> >using standard DTDs, rather than creating your own. Sarah raised the
> >excellent question "Where does a person look to find DTDs? I have searched
> >the web to no avail." The ensuing discussion indicated that there are
> >DTDs out there (and I know that there are, such as the DTD for Push
> >Technology, and the DTD for e-commerce, etc.) but they are scattered about.
> >It occurs to me that what is needed is for a central repository of DTDs.
> >It need not necessarily contain the DTDs but rather pointers to web sites
> >that actually contain the DTDs. Also, as DTDs are created then there will
> >be a web site to put the new DTDs. So, the challenge is for someone to do
> >some research to find the existing DTDs and create a DTD Repository web
> >site. This could initially be a MITRE internal web site (to support MITRE
> >efforts), and then eventually be made into an external site. Any comments?
And then Paul wrote:
> Does anyone know of any such repository of DTDs for XML? Any pointers are
So let me try a response. I do know that Commerce.Net took over the
last month to collect XML tools and applications and references.
There's an InfoWorld article on it
which I'll include below. Unfortunately, I am unable to connect to any
of the forums there
and the rest of the site is kind of sparse right now. I wonder what
kind of schedule they have in mind.
I'm Cc'ing Commerce.Net on this note in case they want to respond.
Note also that there are already some plans in the works to supersede
DTDs with DCDs (Document Content Descriptions):
To quote the CNET article, DCDs improve on DTDs in three principal ways:
> 1. Unlike the DTD, the DCD provides the ability to specify data types.
> For example, if the value, or content, of a tag is the number 120874,
> a DCD will let the developer specify whether that number is a date, a
> time, a time interval, a Boolean value, an integer, a decimal, or some
> other type of data.
> 2. DCDs will let authors create open content models. The way it is now
> with the DTD's closed model, an author cannot add tags to a completed
> DTD. But the DCD will let authors carve out a space for additional
> tags to be specified at some point in the future.
> 3. DCDs allow new flexibility in letting developers reuse tags. For
> example, an invoice written using XML could reuse an address tag set
> within the document. Another XML document also could use that tag set.
> Neither of these capabilities exist with the current DTD.
> DCDs are XML documents; DTDs are written in a different syntax.
Just FYI. Oh, and here's the InfoWorld article I mentioned earlier on
the XML Exchange:
> CommerceNet to use XML Web site for registry
> By Nancy Weil, InfoWorld Electric, Posted at 9:30 AM PT, Jul 16, 1998
> A Web site dedicated to Extensible Markup Language (XML) has been
> acquired by a global Internet-commerce consortium that intends to use
> the site as the core of a registry service to ensure interoperability
> and information exchange among developers.
> XML Exchange (http://www.xmlx.com/), which was launched 10 weeks ago,
> will now be run by CommerceNet, a non-profit I-commerce industry group
> with more than 500 worldwide members, CommerceNet announced. The Web
> site was acquired for an undisclosed sum from XMLSolutions, a Washington
> consulting company.
> XML was finalized as a standard by the World Wide Web Consortium (W3C)
> in February, and within weeks was hailed as the heir apparent to HTML. A
> subset of Standard Generalized Markup Language (SGML), XML allows
> programmers to make it easier to find and index information on the Web.
> HTML cannot identify text. That means, for instance, that HTML cannot
> distinguish when a number is a price. Nor can it determine in a search
> query the specific meaning of a particular word. As a result, a search
> of the word "Boss" might turn up listings for a model of a guitar, the
> musical genre bossa nova, Bossier Parish in Louisiana, the Boston
> Celtics, and an anti-stress page called "My Boss Sucks!" Even trying to
> pare down the search with more exact keywords will result in wildly
> disparate listings.
> As long as programmers of various Web sites agree on definitions --
> "price" or "cost," for example -- then XML-based sites will interoperate
> and that ability is seen as having a major effect on I-commerce in
> particular, not to mention making it easier to search the Web.
> Of course, one hurdle to XML's use is that programmers have to agree on
> definitions, but the registry service set up by CommerceNet is supposed
> to help coordinate the definitions. The definitions are written as tags,
> which is code contained in angled brackets.
> CommerceNet's eRegistry Service is intended to allow developers to
> quickly post new definition tag sets, to ensure accuracy of tag-set
> submissions and downloads, enable availability and keyword searching of
> content, and to create discussion forums, CommerceNet said.
> XML Exchange includes topical forum areas created by members covering a
> range of subjects. The areas, which are being set up now, will allow XML
> programmers to discuss and post information on customizing XML for use
> in vertical industries including automotive, education, genealogy,
> history, insurance, military, real estate, and Web management. It also
> lists resources, such as books, and tracks XML news.
> "XML will have a dramatic impact on the future development and growth of
> electronic commerce," said Randall Whiting, president and chief
> executive officer of CommerceNet, in the written statement.
> The role of XML in advancing I-commerce has been widely underestimated,
> he said. Because the programming language enables interoperability
> between applications, companies, and industries, Whiting predicted that
> XML will allow companies to better integrate supply chains and cooperate
> on product design and development.
> CommerceNet, in Palo Alto, Calif., can be reached at
> XML Solutions, in Washington, can be reached at
Commandment 1. Thou shalt not use a queue as a database.
-- The "10 Q-Mandments,"