DTD syntax is not particularly difficult to learn. You can get a fairly
quick introduction from the developer zone at Project Cool (try
However, although the syntax is not terribly complicated, some DTDs can be.
You need a good understanding of your document structures and their
semantics before you start editing an existing DTD as changes, particularly
to parameter entities, can propagate right through the DTD. Some changes to
a DTD will make existing documents based on that DTD invalid - others will
not. Major revisions to a DTD may mean renaming it to create a new version,
so that you can base new documents on the new DTD whilst not invalidating
It can help if you have a good validating XML editor, as this will:
1) check that your changed DTD is still valid.
2) enable you to check that you can still create documents that have the
structure you expect.
----- Original Message -----
From: Carl Bramblett <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, June 06, 2000 11:46 PM
Subject: DTD Courses? DTD Consulting?
> Hi XMLers,
> My company is currently moving toward authoring in an XML
> environment. I was wondering if the experts out there could
> recommend courses for learning DTDs. Additionally, I would
> very much like to learn about DTD outsourcing leads.
> Basically, our goal is to have the training so we can update the
> DTD as necessary, but not create the full DTD from scratch.
> Many thanks for your input,