Publishers of technology books, eBooks, and videos for creative people

Home > Articles > Web Design & Development > Usability

Web Design Reference Guide

Hosted by

Conformance and Validation

Last updated Oct 17, 2003.

By Molly Holzschlag

Despite the focus on conformance and validation in terms of XHTML, conformance and validation are important no matter which language you're using.

To conform means just that—to adhere to the rules set out within the language and language versions. This means that not only do you use elements and attributes within the definition of the language you choose to use, but you also adhere to that language and language version's concepts.

Validation is used to test conformance. Validation is the process by which you take your document and pass it through a validation tool. This tool takes the DOCTYPE declaration information in your document and compares the syntax in your document to the official language and language version (found in what is known as a DTD-Document Type Definition). If you have conformed to the declared language and version, your document will pass validation. If not, you'll receive errors so that you can go ahead and repair the document in order to achieve conformance.


Although there are a variety of validators found in design and development tools, the validator at the World Wide Web Consortium is considered to be the best: