Web Content Accessibility Guidelines (WCAG) 2.0

The World Wide Web Consortium (W3C) is an international community with a mission to lead the Web to its full potential, which among other means making it possible-to-use for everyone. W3C develops many technical specifications and guidelines. One of them is the document “Web Content Accessibility Guidelines (WCAG) 2.0”.

WCAG 2.0 covers a wide range of recommendations for making Web content accessible for disabled, including blindness and low vision, deafness and hearing loss, learning disabilities, cognitive limitations, limited movement, speech disabilities, photosensitivity and combinations of these. The creators of WCAG 2.0 believe following their guidelines also often makes any Web content more usable to all users and not only users with disabilities.

WCAG 2.0 Guidelines are divided into 4 categories, which are: perceivable, operable, understandable and robust.  All of the information on the Web Information must be presentable in ways they users can perceive, all functionalities must be available from a keyboard (not only by clicking), all of the information, the operation of the user interface must be understandable and the content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies. Each of this 4 principles also has subcategories (guidelines), which are well explained. For each guideline there is a document that shows us how to meet the requirements of the guideline and a document for understanding the guideline. 

The complete document with guidelines is available here: https://www.w3.org/TR/WCAG20/