Priority 1
A Web content developer must satisfy this checkpoint. Otherwise, one or more groups will find it impossible to access information in the document. Satisfying this checkpoint is a basic requirement for some groups to be able to use Web documents.
General
- Provide text equivalents
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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.
1.1
- Convey information without color
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Ensure that all information conveyed with color is also available without color, for example from context or markup.
2.1
- Identify change of natural language
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Clearly identify changes in the natural language of a document's text and any text equivalents (e.g., captions).
4.1
- Organize documents
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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.
6.1
- Dynamic content
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Ensure that equivalents for dynamic content are updated when the dynamic content changes.
6.2
- No flicker
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Until user agents allow users to control flickering, avoid causing the screen to flicker.
7.1
- Use simple language
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Use the clearest and simplest language appropriate for a site's content.
14.1
Images and image maps
- Redundant text links for server-side image maps
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Provide redundant text links for each active region of a server-side image map.
1.2
- Prefer client-side image maps
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Provide client-side image maps instead of server-side image maps except where the regions cannot be defined with an available geometric shape.
9.1
Tables
- Indentify row and column headers
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For data tables, identify row and column headers.
5.1
- Associate data and header cells
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For data tables that have two or more logical levels of row or column headers, use markup to associate data cells and header cells.
5.2
Frames
- Title each frame
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Title each frame to facilitate frame identification and navigation.
12.1
Applets and scripts
- Make pages usable without scripts, etc.
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Ensure that pages are usable when scripts, applets, or other programmatic objects are turned off or not supported. If this is not possible, provide equivalent information on an alternative accessible page.
6.3
Multimedia
- Provide auditory description for multimedia
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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.
1.3
- Synchronize alternatives
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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.
1.4
If all else fails
- Make alternative page
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If, after best efforts, you cannot create an accessible page, provide a link to an alternative page that uses W3C technologies, is accessible, has equivalent information (or functionality), and is updated as often as the inaccessible (original) page.
11.4
Priority 2
A Web content developer should satisfy this checkpoint. Otherwise, one or more groups will find it difficult to access information in the document. Satisfying this checkpoint will remove significant barriers to accessing Web documents.
General
- Ensure sufficient contrast
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Ensure that foreground and background color combinations provide sufficient contrast when viewed by someone having color deficits or when viewed on a black and white screen. [Priority 2 for images, Priority 3 for text].
2.2
- Use appropriate markup language
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When an appropriate markup language exists, use markup rather than images to convey information.
3.1
- Validate documents
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Create documents that validate to published formal grammars.
3.2
- Use CSS
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Use style sheets to control layout and presentation.
3.3
- Use relative units
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Use relative rather than absolute units in markup language attribute values and style sheet property values.
3.4
- Use header elements
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Use header elements to convey document structure and use them according to specification.
3.5
- Use lists
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Mark up lists and list items properly.
3.6
- Mark up quotations
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Mark up quotations. Do not use quotation markup for formatting effects such as indentation.
3.7
- Check for dynamic content
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Ensure that dynamic content is accessible or provide an alternative presentation or page.
6.5
- Avoid blinking
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Until user agents allow users to control blinking, avoid causing content to blink (i.e., change presentation at a regular rate, such as turning on and off).
7.2
- Avoid auto-refresh
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Until user agents provide the ability to stop the refresh, do not create periodically auto-refreshing pages.
7.4
- Avoid auto-redirect
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Until user agents provide the ability to stop auto-redirect, do not use markup to redirect pages automatically. Instead, configure the server to perform redirects.
7.5
- Avoid popups
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Until user agents allow users to turn off spawned windows, do not cause pop-ups or other windows to appear and do not change the current window without informing the user.
10.1
- Use latest W3C technologies
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Use W3C technologies when they are available and appropriate for a task and use the latest versions when supported.
11.1
- Avoid deprecated features of W3C technologies
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Avoid deprecated features of W3C technologies.
11.2
- Divide information up
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Divide large blocks of information into more manageable groups where natural and appropriate.
12.3
- Clearly identify the target of each link
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Clearly identify the target of each link.
13.1
- Provide metadata
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Provide metadata to add semantic information to pages and sites.
13.2
- Provide site map / TOC
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Provide information about the general layout of a site (e.g., a site map or table of contents).
13.3
- Use consistent navigation
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Use navigation mechanisms in a consistent manner.
13.4
Tables
- Ensure TABLEs make sense when linearized
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Do not use tables for layout unless the table makes sense when linearized. Otherwise, if the table does not make sense, provide an alternative equivalent (which may be a linearized version).
5.3
- Don't use structural markup for visual formatting
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If a table is used for layout, do not use any structural markup for the purpose of visual formatting.
5.4
Frames
- Describe FRAMEs
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Describe the purpose of frames and how frames relate to each other if it is not obvious by frame titles alone.
12.2
Forms
- Ensure LABELs are positioned properly
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Until user agents support explicit associations between labels and form controls, for all form controls with implicitly associated labels, ensure that the label is properly positioned.
10.2
- Associate LABELs to their controls
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Associate labels explicitly with their controls.
12.4
Applets and scripts
- Ensure event handlers are device independent
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For scripts and applets, ensure that event handlers are input device-independent.
6.4
- Avoid moving content
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Until user agents allow users to freeze moving content, avoid movement in pages.
7.3
- Make scripts compatible with assistive technologies
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Make programmatic elements such as scripts and applets directly accessible or compatible with assistive technologies [Priority 1 if functionality is important and not presented elsewhere, otherwise Priority 2.]
8.1
- Ensure device-independent operation
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Ensure that any element that has its own interface can be operated in a device-independent manner.
9.2
- Specify logical event handlers
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For scripts, specify logical event handlers rather than device-dependent event handlers.
9.3