The World Wide Web Consortium (W3C) sets and publishes standards for most web programming languages, including HTML 5, XHTML 1.1, CSS Level upto 4, DOM, and SMIL. W3C languages are designed with accessibility in mind. Programming code is considered "valid" when it follows all the rules and conventions specified in the published standards.
Objective:
- Screen readers and other assistive technologies can more accurately interpret and interact with web pages that are built using valid, standard code.
- To ensure that the site is compatible with a wider range of web browsers and devices used by the general public.
Guidelines:
- HTML code should begin with DOCTYPE
- Indicate the programming language that is used by starting your code with a document type declaration such as:<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 5.00 Transitional//EN">
- Refer to the W3C site for full specifications and documentation.
- Use appropriate markup to convey document structure
Validation Technique:
Use W3C Markup Validation service