W3C Web Content Accessibility Guidelines 1 0 1999 Overview of the web accessibility guidelines at RMIT W3C s WAI Level A Conformance http www w3 org TR WCAG10 Praneeth Putlur Rajiv Pandya Rohit Sharma Need users operate in different contexts They may not be able to see hear move or may not be able to process some types of information easily or at all They may have difficulty reading or comprehending text They may not have or be able to use a keyboard or mouse They may have a text only screen a small screen or a slow Internet connection They may not speak or understand fluently the language in which the document is written They may be in a situation where their eyes ears or hands are busy or interfered with e g driving to work working in a loud environment etc They may have an early version of a browser a different browser entirely a voice browser or a different operating system The guidelines are intended for all web content developers page authors and site designers and for developers of authoring tools The primary goal of these guidelines is to promote accessibility Following these guidelines will also help people find information on the Web more quickly Text Equivalent of an Image The guidelines do not suggest avoiding images as a way to improve accessibility Instead they explain that providing a text equivalent of the image will make it accessible For example consider a text equivalent for a photographic image of the Earth as seen from outer space If the purpose of the image is mostly that of decoration then the text Photograph of the Earth as seen from outer space might fulfill the necessary function Themes of Accessible Design Ensuring Graceful Transformation Making Content Understandable and Navigable Ensuring Graceful Transformation Provide text since text can be rendered in ways that are available to almost all browsing devices and accessible to almost all users Create documents that do not rely on one type of hardware Making Content Understandable and Navigable Providing navigation tools and orientation information in pages will maximize accessibility and usability Not all users can make use of visual clues such as image maps proportional scroll bars side by side frames or graphics that guide sighted users of graphical desktop browsers Priorities The checkpoint definitions in each guideline explain how the guideline applies in typical content development scenarios Each checkpoint has a priority level assigned by the Working Group based on the checkpoint s impact on accessibility Priority 1 A Web content developer must satisfy this checkpoint Priority 2 A Web content developer should satisfy this checkpoint Priority 3 A Web content developer may address this checkpoint Conformance Conformance Level A all Priority 1 checkpoints are satisfied Conformance Level Double A all Priority 1 and 2 checkpoints are satisfied Conformance Level Triple A all Priority 1 2 and 3 checkpoints are satisfied Claims of conformance to this document must use one of the following two forms Form 1 Specify The guidelines title Web Content Accessibility Guidelines 1 0 The guidelines URI http www w3 org TR 1999 WAIWEBCONTENT 19990505 The conformance level satisfied A Double A or Triple A The scope covered by the claim e g page site or defined portion of a site Form 2 Include on each page claiming conformance one of three icons provided by W3C and link the icon to the appropriate W3C explanation of the claim GUIDELINES There are fourteen guidelines or general principles of accessible design A list of checkpoint definitions 1 Provide equivalent alternatives to auditory and visual content Provide content that when presented to the user conveys essentially the same function or purpose as auditory or visual content 1 1 Provide a text equivalent for every non text element e g via alt longdesc or in element content This includes images graphical representations of text including symbols image map regions animations e g animated GIFs applets and programmatic objects ascii art frames scripts images used as list bullets spacers graphical buttons sounds played with or without user interaction stand alone audio files audio tracks of video and video Priority 1 1 2 Provide redundant text links for each active region of a server side image map Priority 1 1 3 Until user agents can automatically read aloud the text equivalent of a visual track provide an auditory description of the important information of the visual track of a multimedia presentation Priority 1 1 4 For any time based multimedia presentation e g a movie or animation synchronize equivalent alternatives e g captions or auditory descriptions of the visual track with the presentation Priority 1 2 Don t rely on color alone Ensure that text and graphics are understandable when viewed without color 2 1 Ensure that all information conveyed with color is also available without color for example from context or markup Priority 1 3 Use markup and style sheets and do so properly Mark up documents with the proper structural elements Control presentation with style sheets rather than with presentation elements and attributes 4 Clarify natural language usage Use markup that facilitates pronunciation or interpretation of abbreviated or foreign text 4 1 Clearly identify changes in the natural language of a document s text and any text equivalents e g captions Priority 1 For example in HTML use the lang attribute In XML use xml lang 5 Create tables that transform gracefully Ensure that tables have necessary markup to be transformed by accessible browsers and other user agents 5 1 For data tables identify row and column headers Priority 1 For example in HTML use TD to identify data cells and TH to identify headers 5 2 For data tables that have two or more logical levels of row or column headers use markup to associate data cells and header cells Priority 1 For example in HTML use THEAD TFOOT and TBODY to group rows COL and COLGROUP to group columns and the axis scope and headers attributes to describe more complex relationships among data 6 Ensure that pages featuring new technologies transform gracefully Ensure that pages are accessible even when newer technologies are not supported or are turned off 6 1 Organize documents so they may be read without style sheets For example when an HTML document is rendered without associated style sheets it must still be possible to read the document Priority 1 When content is organized logically it will be rendered in a