Example for Checkpoint
3.2 - Create documents that validate to published formal grammars.

In general the overall accessibility of any Web page will be improved if you adhere to the standards for the web-presentation language you are using. The major reason for this is that most developers of assistive technology or accessible web technology have based their accessibility features on the premise that content authors are following the standards.

We also assume that most Web browsers will more or less follow the published standards. Writing the "cleanest" code possible should ensure your pages will look best across the widest range of Web display technology.

If your coding meets the requirements of a particular grammar, use the DOCTYPE statement as the first line of your HTML file. For example, the following DOCTYPE statement would indicate to servers, browsers and validators that you expect your code to conform to the HTML 4.0 Transitional document type descriptor (or DTD). The DTD is the "formal" grammar of the language.

Quite a few sites, including the W3C, offer HTML validation. There are even sites that will validate your HTML and check your page for some aspects of accessibility. See the section on Validation and Testing in this curriculum for more details.