XHTML by Example

Why Validate?

Because XHTML requires that documents be both well-formed and valid, and validity itself requires well-formedness, one check can ascertain that a document conforms to both. Practically, validating your documents provides the experienced Web author benefit in finding errors that were unintentional, such as typos or a forgotten closing tag.

Typo Control

One of the most rudimentary uses of validation is to catch some of the simple problems, such as typographical errors. Any developer who's not using an authoring tool that creates tags for him is bound to make a few typos in any given document. Rather than having to painstakingly read each page for problems, a quick pass through the validator can point them out in seconds (see Figure ...