XHTML by Example

Building Blocks of a Basic DTD

A DTD can be as simple as a single element declaration, provided, of course, that you're satisfied writing a document using just a single element! Before we can begin building or reading DTDs, you must understand the notation used.

EBNF: The Syntax of DTDs

DTDs are primarily intended for machine consumption, not human. When working with machines, success often depends on being extremely concise. In the earlier days of computing, 1960 to be specific, two computer scientists devised a formal notation that described the syntax of the ALGOL60 computer language. The notation was named after the pair, and became known as Backus Naur Form.

Over the years as the complexity of computer languages increased, the notation ...