About WCAG 1.0 Accessibility

CSE HTML Validator helps an organization comply (but cannot guarantee compliance) with the W3C's Web Content Accessibility Guidelines 1.0 (WCAG 1.0). These are guidelines for web developers and developers of authoring tools to help make them more accessible to people with disabilities. These guidelines were published as a W3C Recommendation in 1999 and are now superseded by WCAG 2.0.

Developers must satisfy priority 1 checkpoints, should satisfy priority 2 checkpoints, and may address priority 3 checkpoints. See Section 4 of the WCAG 1.0 guidelines for more information.

WCAG 1.0 Items Checked (may not be a complete list)

Displays an error message for missing alternative text ("alt" attribute) for the "applet", "area", "img", and "input" (when type="image") elements. [P1, 1.1]

Displays an error message for missing alternative representation for the "object" element. [P1, 1.1]

Displays a warning message for a missing text alternative (in the body) for "applet" elements. [P1, 1.1] (Nev v9.9930)

Displays a warning message for empty alternative text (alt="") for "area" elements. [P1, 1.1] (New v9.9930)

Displays a warning message for missing title text ("title" attribute) for "area" elements. [P1, 1.1] (New v9.9930)

Displays a message for a missing "longdesc" attribute (to specify a text alternative of the frame) for the "frame" and "iframe" elements. [P1, 1.1]

Displays a message about using a text alternative (in case scripting is turned off or not supported) when the "script" element is used. [P1, 1.1]

Displays a message to provide redundant text links when the "ismap" attribute is used with the "img" element. [P1, 1.2]

Displays a warning message if the brightness or color difference of specified foreground and background colors is below minimum recommendations. [P3, 2.2]

Displays a message about the importance of making sure that documents validate to published formal grammars and are "well formed" if only an accessibility check is done. [P2, 3.2]

Displays a warning message when presentational elements are used instead of style sheets. [P2, 3.3]

Displays a message when the "small" element is used and provides information about its presentation vs semantic use (in HTML5, "small" has semantic meaning). [P2, 3.3] (New v10.9921)

Displays a warning message about using relative units rather than absolute units in style property values. [P2, 3.4]

Displays a warning message if heading elements appear out of order. [P2, 3.5]

Displays a message for missing "lang" and "xml:lang" attributes (to specify the natural primary language of a document) for the "html" element. [P3, 4.3]

Displays a warning message about using table row and column headers for data tables if the "th" element is not used in the table. [P1, 5.1]

Displays a message about using markup to associate data cells and header cells in data tables with two or more logical levels of row or column headers. [P2, 5.2]

Displays a message recommending to avoid using tables for layout (unless they make sense when linearized) and to not use any structural markup for the purpose of visual formatting when the "table" element is used. [P2, 5.3, 5.4]

Displays a message for a missing "summary" attribute (to provide a brief overview of how data has been organized in the table or a brief explanation of how to navigate or use the table) when the "table" element is used. [P3, 5.5]

Displays a message that documents should be able to be read without style sheets when a style sheet is used. [P1, 6.1]

Displays a warning message if "javascript:" is used in the "href" attribute of an "a" element. [P1, 6.3]

Displays a message about making sure pages are usable when scripts, applets, or other programmatic objects are turned off or not supported when href="#" and an "onclick" attribute is used or when scripts, applets, or other programmatic objects are turned off or not supported. [P1, 6.3]

Displays a warning message about causing content to blink when the "blink" element is used. [P2, 7.2]

Displays a warning message if it appears that a meta tag is trying to do a non-zero second page refresh or auto-redirect. [P2, 7.4, 7.5]

Displays a message recommending client-side image maps instead of server-side image maps when the "ismap" attribute is used with the "img" element. [P1, 9.1]

Displays a message for device-dependent event handlers like "onmouseout" and "onmouseover" and suggest logical event handlers instead. [P2, 9.3]

Displays a comment about using keyboard shortcuts to important links (often done using the "accesskey" attribute). [P3, 9.5]

Displays a comment if "a" elements have been used but not one "accesskey" attribute has been used with any of the "a" elements. [P3, 9.5]

Displays a message if a "target" attribute is used to open a new window (the message is a warning if the link text does not contain "new window" to notify the user). [P2, 10.1]

Displays a warning message if adjacent links are not separated by non-link, printable characters. [P3, 10.5]

Displays a warning message if a frame title does not appear to be useful or meaningful. [P1, 12.1]

Displays an error message for a missing "title" attribute (to label the frame, describe the contents, and facilitate frame identification and navigation) for the "frame" and "iframe" elements. [P1, 12.1]

Displays a warning message for "input" (of certain types), "select", and "textarea" control elements if they do not have explicitly associated labels. [P2, 12.4]

Displays a warning message if the same link text has been used to link to different resources. [P2, 13.1]

Displays a warning message if the document does not appear to have an appropriate or descriptive title. [P2, 13.2]

Displays a warning message if there is no "title" element in the "head" section. [P2, 13.2]