Web Accessibility and Usability Standards

Text Equivalents

All non-text content that is presented to the user must have a text alternative that presents equivalent information (e.g., via "ALT," "LONGDESC," or in element content), except for the situations listed below. WCAG2 Techniques for Text Equivalents

Controls-Input – If non-text content is a control or accepts user input, then it has a name that describes its purpose.

Media, Test, Sensory – If non-text content is multimedia, live audio-only or live video-only content, a test or exercise that must be presented in non-text format, or primarily intended to create a specific sensory experience, then text alternatives at least identify the non-text content with a descriptive text label.

CAPTCHA – If the purpose of non-text content is to confirm that content is being accessed by a person rather than a computer, then text alternatives that identify and describe the purpose of the non-text content are provided and alternative forms in different modalities are provided to accommodate different disabilities.

Decoration, Formatting, Invisible Objects – If non-text content is pure decoration, or used only for visual formatting, or if it is not presented to users, then it is implemented such that it can be ignored by assistive technology.

Equivalent Alternatives for Multimedia

Any prerecorded multimedia presentation that contains visual, speech, or other audio information necessary for the comprehension of the content must have an equivalent alternative (e.g., captions, an auditory description of the visual track, or a separate text description of the video) WCAG1 Techniques for Equivalent Alternatives for Multimedia

Captions (Multimedia) – Any prerecorded multimedia, except for multimedia alternatives to text that are clearly labeled as such, containing speech or other audio information necessary for the comprehension of the content must provide captions. WCAG2 Techniques for Captions

Audio Description or Full Text Alternative – Any prerecorded multimedia that contains visual information necessary for the comprehension of the content must provide a synchronized audio description of the video (or of the important information of the visual track). If a synchronized alternative is not possible, a full text alternative for multimedia including any interaction is recommended. WCAG2 Techniques for Audio Description

Note: If all of the information in the video track is already provided in the audio track, no audio description is necessary.

Color

Color coding shall not be used as the only means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. Web pages must be designed so that all information conveyed with color is also simultaneously visually evident without color, for example from context or markup. WCAG1 Techniques for Color   WCAG2 Techniques for Color

Style Sheets

Documents shall be organized so they are readable without requiring an associated style sheet. For example, when an HTML document is rendered without associated style sheets, it must still be possible to read the document. WCAG1 Techniques for Style Sheets

Server-side Image Maps

Redundant text links shall be provided for each active region of a server-side image map. WCAG2 Techniques for Server-side Image Maps

Client-side Image Maps

Client-side image maps shall be provided instead of server-side image maps except where the regions cannot be defined with an available geometric shape. WCAG1 Techniques for Client-side Image Maps

Scripts

When pages utilize scripting languages to display content, or to create interface elements, the information provided by the script must be identified with functional text that can be read by assistive technology.

Frames

Frames shall be titled with text that facilitates frame identification and navigation. For example, in HTML use the "title" attribute on FRAME elements.

Table Headers

Row and column headers shall be identified for data tables. For example, in HTML, use TD to identify data cells and TH to identify headers.

Complex Tables

Markup shall be used to associate data cells and header cells for data tables that have two or more logical levels of row or column headers. 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.

Forms

When electronic forms are designed to be completed online, the form shall allow people using assistive technology to access the information, field elements, and functionality required for completion and submission of the form, including all directions and cues. WCAG2 Techniques for Forms

Applets and Plug-ins

When a Web page requires that an applet, plug-in, or other application be present on the client system to interpret page content, the page must provide a link to a plug-in or applet that meets the software provisions of TAC §213.30.

Keyboard

All functionality of the content shall be operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying function requires input that depends on the path of the user's movement and not just the endpoints. WCAG2 Techniques for Keyboard

Note 1: This exception relates to the underlying function, not the input technique. For example, if using handwriting to enter text, the input technique (handwriting) requires path dependent input but the underlying function (text input) does not.

Note 2: This does not forbid and should not discourage providing mouse input or other input methods in addition to keyboard operation.

Alternate Text-Only Versions

Alternate text-only versions of Web sites are not recommended. However if, after best efforts, you cannot create an accessible page, provide a link to an alternate text-only page that is accessible, has equivalent information or functionality, and is updated as often as the inaccessible (original) page. WCAG1 Techniques for Alternative Text-Only Versions

Color Contrast

Text (and images of text) must have a contrast ratio of at least 5:1, except if the text is pure decoration. Larger-scale text or images of text can have a contrast ratio of 3:1. WCAG2 Techniques for Color Contrast

Audio Turnoff

If any audio plays automatically for more than 3 seconds, there must be either a mechanism to pause or stop the audio, or a mechanism to control audio volume which can be set independently of the system volume. WCAG2 Techniques for Audio Turnoff

Dynamic Content

Equivalents for dynamic content must be updated when the dynamic content changes. WCAG1 Techniques for Dynamic Content

Parsing

Content implemented using markup languages must have elements with complete start and end tags, except as allowed by their specifications, and must be nested according to their specifications. WCAG2 Techniques for Parsing

User Interface Components

For all user interface components, including form elements and those generated by scripts

• the name and role must be programmatically determined;
• states, properties, and values that can be set by the user must be programmatically determined and programmatically set; and
• notification of changes to these items shall be available to user agents, including assistive technologies. WCAG2 Techniques for UI Components
  

Note: This success criterion is primarily for Web authors who develop or script their own user interface controls. For example, standard HTML controls already meet this provision when used according to specification.

Link Purpose (context)

On Web pages, it must be possible to determine the purpose of each link from the link text or the link text together with its programmatically determined link context. WCAG2 Techniques for Link Purpose

Meaningful Sequence

When the sequence in which content is presented affects its meaning, a correct reading sequence must be programmatically determined. The sequential navigation of interactive components must be consistent with that reading sequence. WCAG2 Techniques for Meaningful Sequence

Size, Shape, Location

Instructions provided for understanding and operating content must not rely on shape, size, visual location, or orientation of components. WCAG2 Techniques for Size, Shape, Location

Three Flashes or Less

Web pages must not contain anything that flashes more than three times in any one second period (i.e., has a frequency greater than 2Hz and lower than 55Hz), or the flashing is below the general flash and red flash thresholds. WCAG2 Techniques for Three Flashes or Less

Timing

For each time limit that is set by the content, at least one of the following must be true: WCAG2 Techniques for Timing

• Turn off – The user must be allowed to turn off the time limit before encountering it; or
• Adjust – The user must be allowed to adjust the time limit before encountering it over a wide range that is at least ten times the length of the default setting; or
• Extend – The user must be warned before time expires and given at least 20 seconds to extend the time limit with a simple action (for example, "hit any key"), and the user is allowed to extend the time limit at least ten times; or
• Real-time Exception – The time limit must be a required part of a real-time event (for example, an auction), and no alternative to the time limit is possible; or
• Essential Exception – The time limit must be part of an activity where timing is essential (for example, time-based testing) and time limits cannot be extended further without invalidating the activity.

Bypass Option

A mechanism shall be provided that permits users to bypass blocks of content or navigation links that are repeated on multiple Web pages. WCAG2 Techniques for Bypass Option

Blinking

Web pages shall be designed such that content does not blink for more than three seconds, or there shall be a method available to stop all blinking content in the Web page. WCAG2 Techniques for Blinking

Pausing

Moving, blinking, scrolling, or auto-updating information must allow pausing by the user unless it is part of an activity where timing or movement is essential. Content that is pure decoration must at least allow stopping by the user. WCAG2 Techniques for Pausing

Language of Page

Changes in the natural language of a document's text and any text equivalents (e.g., captions) must be clearly identified. For example, in HTML use the "lang" attribute. In XML, use "xml:lang". WCAG2 Techniques for Language of Page

Page Title

Web pages must have descriptive titles. WCAG2 Techniques for Page Title

Consistent Identification

Components that have the same functionality within a set of Web pages must be identified consistently. WCAG2 Techniques for Consistent Identification

Consistent Navigation

Navigational mechanisms that are repeated on multiple Web pages within a set of Web pages shall occur in the same relative order each time they are repeated, unless a change is initiated by the user. WCAG2 Techniques for Constant Navigation

Focus Order

If a Web page can be navigated sequentially, focusable components shall receive focus in an order that follows information and relationships conveyed through presentation. WCAG2 Techniques for Focus Order

On Focus

When any component receives focus, it must not initiate a change of context. WCAG2 Techniques for OnFocus

On Input

Changing the setting of any user interface component must not automatically cause a change of context unless the user has been advised of the behavior before using the component. WCAG2 Techniques for On Input

Error Identification

If an input error is automatically detected, the item that is in error must be identified and described to the user in text. WCAG2 Techniques for Error Identification