XML by Example

Initially, XML documents were developed in isolation. One would develop a

DTD for a specific application—that is a magazine, an order, or a channel—

as we saw in Chapter 2, “The XML Syntax.” The elements defined in the

DTD would be specific to that application. There is little reuse of elements

except, maybe, by cutting and pasting old DTDs into new ones.

Thanks to namespaces, it is possible to develop reusable elements—that is,

elements that can be reused in multiple documents. This is a new approach

for document development.

Increasingly, the W3C and other groups work on such reusable elements.

Two examples are XML style sheets and digital signatures ...