O'Reilly logo

Effective XML: 50 Specific Ways to Improve Your XML by Elliotte Rusty Harold

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Document Type Definitions

If the W3C XML Schema Language is a Torx screwdriver, then DTDs are the old reliable flathead screwdriver, not nearly as sexy but a lot more practical and a lot easier to find at the corner store. Contrary to popular belief, schemas do not replace DTDs. DTDs are an extremely well-tested, well-understood, broadly supported, compact syntax for expressing constraints on XML documents. Furthermore, DTDs can do things that none of the other schema languages can accomplish, notably entity definition. Finally, a document can have both a schema and a DTD.

Don't reject DTDs simply because they're not as hip as schemas. Indeed, if your constraints are limited to the element and attribute structure of a document and do not involve ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required