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Priorities

PriorityDescription
1
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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.
2
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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.
3
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A Web content developer may address this checkpoint. Otherwise, one or more groups will find it somewhat difficult to access information in the document. Satisfying this checkpoint will improve access to Web documents.


Priority 1 checkpoints [up]

Guideline 11.1Provide a text equivalent for every non-text element (e.g., via "alt", "longdesc", or in element content).
1.2Provide redundant text links for each active region of a server-side image map.
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.
1.4For 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.
Guideline 22.1Ensure that all information conveyed with color is also available without color, for example from context or markup.
Guideline 44.1Clearly identify changes in the natural language of a document's text and any text equivalents (e.g., captions).
Guideline 55.1For data tables, identify row and column headers.
5.2For data tables that have two or more logical levels of row or column headers, use markup to associate data cells and header cells.
Guideline 66.1Organize 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.
6.2Ensure that equivalents for dynamic content are updated when the dynamic content changes.
6.3Ensure 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.
Guideline 77.1Until user agents allow users to control flickering, avoid causing the screen to flicker.
Guideline 88.1Make 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.]
Guideline 99.1Provide client-side image maps instead of server-side image maps except where the regions cannot be defined with an available geometric shape.
Guideline 1111.4If, 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.
Guideline 1212.1Title each frame to facilitate frame identification and navigation.
Guideline 1414.1Use the clearest and simplest language appropriate for a site's content.

Priority 2 checkpoints [up]

Guideline 22.2Ensure 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]
Guideline 33.1When an appropriate markup language exists, use markup rather than images to convey information.
3.2Create documents that validate to published formal grammars.
3.3Use style sheets to control layout and presentation.
3.4Use relative rather than absolute units in markup language attribute values and style sheet property values.
3.5Use header elements to convey document structure and use them according to specification.
3.6Mark up lists and list items properly.
3.7Mark up quotations. Do not use quotation markup for formatting effects such as indentation.
Guideline 55.3Do 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).
5.4If a table is used for layout, do not use any structural markup for the purpose of visual formatting.
Guideline 66.4For scripts and applets, ensure that event handlers are input device-independent.
6.5Ensure that dynamic content is accessible or provide an alternative presentation or page.
Guideline 77.2 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).
7.3Until user agents allow users to freeze moving content, avoid movement in pages.
7.4Until user agents provide the ability to stop the refresh, do not create periodically auto-refreshing pages.
7.5Until user agents provide the ability to stop auto-redirect, do not use markup to redirect pages automatically. Instead, configure the server to perform redirects.
Guideline 88.1Make 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.]
Guideline 99.2Ensure that any element that has its own interface can be operated in a device-independent manner.
9.3For scripts, specify logical event handlers rather than device-dependent event handlers.
Guideline 1010.1Until 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.
10.2 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.
Guideline 1111.1Use W3C technologies when they are available and appropriate for a task and use the latest versions when supported.
11.2Avoid deprecated features of W3C technologies.
Guideline 1212.2Describe the purpose of frames and how frames relate to each other if it is not obvious by frame titles alone.
12.3Divide large blocks of information into more manageable groups where natural and appropriate.
12.4Associate labels explicitly with their controls.
Guideline 1313.1Clearly identify the target of each link.
13.2Provide metadata to add semantic information to pages and sites.
13.3Provide information about the general layout of a site (e.g., a site map or table of contents).
13.4Use navigation mechanisms in a consistent manner.

Priority 3 checkpoints [up]

Guideline 11.5 Until user agents render text equivalents for client-side image map links, provide redundant text links for each active region of a client-side image map.
Guideline 22.2Ensure 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]
Guideline 44.2Specify the expansion of each abbreviation or acronym in a document where it first occurs.
4.3Identify the primary natural language of a document.
Guideline 55.5Provide summaries for tables.
5.6Provide abbreviations for header labels.
Guideline 99.4Create a logical tab order through links, form controls, and objects.
9.5Provide keyboard shortcuts to important links (including those in client-side image maps), form controls, and groups of form controls.
Guideline 1010.3Until user agents (including assistive technologies) render side-by-side text correctly, provide a linear text alternative (on the current page or some other) for all tables that lay out text in parallel, word-wrapped columns.
10.4Until user agents handle empty controls correctly, include default, place-holding characters in edit boxes and text areas.
10.5Until user agents (including assistive technologies) render adjacent links distinctly, include non-link, printable characters (surrounded by spaces) between adjacent links.
Guideline 1111.3Provide information so that users may receive documents according to their preferences (e.g., language, content type, etc.)
Guideline 1313.5Provide navigation bars to highlight and give access to the navigation mechanism.
13.6Group related links, identify the group (for user agents), and, until user agents do so, provide a way to bypass the group.
13.7If search functions are provided, enable different types of searches for different skill levels and preferences.
13.8Place distinguishing information at the beginning of headings, paragraphs, lists, etc.
13.9Provide information about document collections (i.e., documents comprising multiple pages.).
13.10Provide a means to skip over multi-line ASCII art.
Guideline 1414.2Supplement text with graphic or auditory presentations where they will facilitate comprehension of the page.
14.3Create a style of presentation that is consistent across pages.