WAI Glossary

W3C Working Draft 28 February 2003

This version:



Status of this Document


Table of Contents

1 Terms defined in WAI documents
1. 'A' - Terms that begin with the letter 'A'
1. 'B' - Terms that begin with the letter 'B'
1. 'C' - Terms that begin with the letter 'C'
1. other letters
2 Definitions from non-WAI resources
3 To do's
4 References

1 Terms defined in WAI documents

1. 'A' - Terms that begin with the letter 'A'


Within these guidelines, "accessible Web content" and "accessible authoring tool" mean that the content and tool can be used by people regardless of disability. To understand the accessibility issues relevant to authoring tool design, consider that many authors may be creating content in contexts very different from your own:

  • 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 display, or a small screen.

Accessible design will benefit people in these different authoring scenarios and also many people who do not have a physical disability but who have similar needs.

Example: Someone may be working in a noisy environment and thus require an alternative re of audio information. Similarly, someone may be working in an eyes-busy environment and thus require an audio equivalent to information they cannot view. Users of small mobile devices (with small screens, no keyboard, and no mouse) have similar functional needs as some users with disabilities.

See also:Accessible

Accessibility Awareness

An "accessibility-aware" application is one that has been designed to account for authors' differing needs, abilities, and technologies. In the case of authoring tools, this means that (1) care has been taken to ensure that the content produced by user-authors is accessible and (2) that the user interface has been designed to be usable with a variety of display and control technologies.

Accessibility Information

"Accessibility information" is content, including information and markup, that is used to improve the accessibility of a document. Accessibility information includes, but is not limited to, equivalent alternative information.

Accessibility Permission

A PDF file can be encrypted (PDF 1.1) to protect its contents from unauthorized access. PDF's standard security handler defines a set of access privileges for a document, including privileges such as modifying the document's contents, copying text and graphics from the document, and printing the document. In PDF 1.4, this set includes accessibility permission, which controls whether the contents of the document are available via standard accessibility APIs to screen readers and other assistive technology.

Accessibility Problem

Inaccessible Web content or authoring tools cannot be used by some people with disabilities. The Web Content Accessibility Guidelines 1.0 [WCAG10] describes how to create accessible Web content. See also:


Content is accessible when it may be used by someone with a disability.

Editorial note
Weak definition. Needs work.

Accessible Authoring Practice

"Accessible authoring practices" improve the accessibility of Web content. Both authors and tools engage in accessible authoring practices.

Example:, authors write clearly, structure their content, and provide navigation aids. Tools automatically generate valid markup and assist authors in providing and managing appropriate equivalent alternatives.


An identifier formed from some of the letters (often the initials) of a phrase and used as an abbreviation.



Active Element


Aging-Related Conditions

Changes in people's functional ability due to aging can include subtle and/or gradual changes in abilities or a combination of abilities including vision, hearing, dexterity and memory. Any one of these limitations can affect an individual's ability to access Web content.


An "alert" draws the author's attention to an event or situation. It may require a response from the author. An alert warns the author that there are problems that need to be addressed. Attracting the author's attention artfully can be challenging, since author perceptions of alerts, prompts, and warnings can influence opinions of the tool and even of accessible authoring.

An Unintrusive Alert is an alert such as an icon, underlining, or gentle sound that can be presented to the author without necessitating immediate action.

Example: In some word processors misspelled text is highlighted without forcing the author to make immediate corrections. These alerts allow authors to continue editing with the knowledge that problems will be easy to identify at a later time. However, authors may become annoyed at the extra formatting or may choose to ignore the alerts altogether.

An Interruptive Alert is an informative message that interrupts the editing process for the author.

Example: Interruptive alerts are often presented when an author's action could cause a loss of data. Interruptive alerts allow problems to be brought to the author's attention immediately. However, authors may resent the constant delays and forced actions. Many people prefer to finish expressing an idea before returning to edit its format.


Alternative Information

Content is "equivalent" to other content when both fulfill essentially the same function or purpose upon presentation to the user. Equivalent alternatives play an important role in accessible authoring practices since certain types of content may not be accessible to all users (e.g., video, images, audio, etc.). Authors are encouraged to provide text equivalents for non-text content since text may be rendered as synthesized speech for individuals who have visual or learning disabilities, as braille for individuals who are blind, or as graphical text for individuals who are deaf or do not have a disability. For more information about equivalent alternatives, please refer to the Web Content Accessibility Guidelines WCAG 1.0. See also: Equivalent Alternative (ATAG 1.0), Text Equivalent (WCAG 1.0)

Alternative Keyboards or Switches

Alternate keyboards or switches are hardware or software devices used by people with physical disabilities, that provide an alternate way of creating keystrokes that appear to come from the standard keyboard.

Examples: Include keyboard with extra-small or extra-large key spacing, keyguards that only allow pressing one key at a time, on-screen keyboards, eyegaze keyboards, and sip-and-puff switches. Web-based applications that can be operated entirely from the keyboard, with no mouse required, support a wide range of alternative modes of input.


@@is this a ref to Core or?? it says "WCAG10 Tech In this document, the term "animation" refers to any visual movement effect created automatically (i.e., without manual user interaction). This definition of animation includes video and animated images. Animation techniques include:

  • graphically displaying a sequence of snapshots within the same region (e.g., as is done for video and animated images). The series of snapshots may be provided by a single resource (e.g., an animated GIF image) or from distinct resources (e.g., a series of images downloaded continuously by the user agent).

  • scrolling text (e.g., achieved through markup or style sheets).

  • displacing graphical objects around the viewport (e.g., a picture of a ball that is moved around the viewport giving the impression that it is bouncing off of the viewport edges). For instance, the SMIL 2.0 [SMIL20] animation modules explain how to create such animation effects in a declarative manner (i.e., not by composition of successive snapshots).



A Java program inserted into a Web page that relies on a browser to provide the environment in which it can run. Applets are essentially guests of the browser. The browser takes care of their welfare and provides and manages access to the platform specific services.


Application Programming Interface (API)

An application programming interface (API) defines how communication may take place between applications.

A device API defines how communication may take place with an input or output device such as a keyboard, mouse, video card, et

A standard device API is one that is considered standard for that particular device on a given operating or windowing system.


This document uses the term "attribute" as used in SGML and XML [XML] : Element types may be defined as having any number of attributes. Some attributes are integral to the accessibility of content (e.g., the "alt", "title", and "longdesc" attributes in HTML).

Example: Below, the attributes of the beverage element type are "flavour", which has the value "lots", and "colour", which has the value "red": <beverage flavour="lots" colour="red">my favourite</ beverage>

Authoring Tool

An "authoring tool" is any software that is used to produce content for publishing on the Web. Authoring tools include:

Markup Editing Tools

Editing tools specifically designed to produce Web content (e.g., WYSIWYG HTML and XML editors)

Multimedia Creation Tools

Tools that produce multimedia, especially where it is intended for use on the Web (e.g., video production and editing suites, SMIL authoring packages)

Content Management Tools

Tools for site management or site publication, including tools that automatically generate Web sites dynamically from a database, on-the-fly conversion and Web site publishing tools

Programming Tools

Tools that offer the option of saving material in a Web format (e.g., word processors, spread-sheet or desktop publishing packages)

Layout Management Tools

Tools for management of layout (e.g., CSS, XSLT and JSS formatting tools)

Transformation Filtering Tools

Tools for management of layout (e. Tools that transform documents into Web formats (e.g., filters to transform desktop publishing formats to HTML)

Editorial note
make the following links: WYSIWYG, HTML, XML, SMIL, CSS, XSLT and JSS

Automated Markup Insertion Function

"Automated markup insertion functions" are the features of an authoring tool that allow the author to produce markup without directly typing it. This includes a wide range of tools from simple markup insertion aids (such as a bold button on a toolbar) to markup managers (such as table makers that include powerful tools such as "split cells" that can make multiple changes) to high level site building wizards that produce almost complete documents on the basis of a series of author preferences.

1. 'B' - Terms that begin with the letter 'B'

Backward Compatible

Design that continues to work with earlier versions of a language, program, etc.


Blindness involves a substantial, uncorrectable loss of vision in both eyes.


A primitive data type that only can have values of true or false. As in radio buttons. Also, a variable of Boolean type or a function with Boolean arguments or result. The most common Boolean functions are AND, OR and NOT.

Braille (and refreshable Braille display)

Braille uses six raised dots in different patterns to represent letters and numbers to be read by people who are blind with their fingertips. An image of the word "Accessible" in braille follows:

Editorial note
insert braille images here

A braille display, commonly referred to as a "dynamic braille display," raises or lowers dot patterns on command from an electronic device, usually a computer. The result is a line of braille that can change from moment to moment. Current dynamic braille displays range in size from one cell (six or eight dots) to an eighty-cell line, most having between twelve and twenty cells per line.

Braille is a system using six to eight raised dots in various patterns to represent letters and numbers that can be read by the fingertips. Braille systems vary greatly around the world. Some "grades" of braille include additional codes beyond standard alpha-numeric characters to represent common letter groupings (e.g., "th," "ble" in Grade II American English braille) in order to make braille more compact. An 8-dot version of braille has been developed to allow all ASCII characters to be represented. Dynamic or refreshable braille involves the use of a mechanical display where dots (pins) can be raised and lowered dynamically to allow any braille characters to be displayed.

1. 'C' - Terms that begin with the letter 'C'


"Captions" are essential text equivalents for movie audio. Captions consist of a text transcript of the auditory track of the movie (or other video presentation) that is synchronized with the video and auditory tracks. Captions are generally rendered graphically and benefit people who can see but are deaf, hard-of-hearing, or cannot hear the audio.

Editorial note
add termrefs to text equivalents, text transcript, presentation

Check for

As used in checkpoint 4.1, "check for" can refer to three types of checking:

  1. In some instances, an authoring tool will be able to check for accessibility problems automatically. Example: Checking for validity ( checkpoint 2.2) or testing whether an image is the only content of a link.

  2. In some cases, the tool will be able to "suspect" or "guess" that there is a problem, but will need confirmation from the author.

    Example: In making sure that a sensible reading order is preserved a tool can present a linearized version of a page to the author.

  3. In some cases, a tool must rely mostly on the author, and can only ask the author to check.

    Example: The tool may prompt the author to verify that equivalent alternatives for multimedia are appropriate. This is the minimal standard to be satisfied. Subtle, rather than extensive, prompting is more likely to be effective in encouraging the author to verify accessibility where it cannot be done automatically.

Editorial note
"checkpoint 4.1" and "checkpoint 2.2" are links in the ATAG doc


Proposed for [WCAG20] A description or template of an object that describes the responsibilities, the operations, and the state, which can then be used to create instancess.

Example: A Car class, which could be used as the template for instances of a class such as myGreyHonda or yourPurpleBeetle.

Client-side scripting

Proposed for [WCAG20] Web programming that sends instructions for actions to be performed on the client, or user's, computer, such as changing the appearance of a page in the user's browser. In order to display the page or change as intended, the user's system must be able to recognize and process the programming. [NCI]

Cognitive and Neurological Disabilities


Editorial note
This lists the cognitive and neurological disabilities described in the document, but does not define them (i.e., there is more info in the document).
  1. Dyslexia, Dyscalculia

  2. Attention Deficit Disorder, or ADD

  3. Attention Deficit Hyperactive Disorder, or ADHD

  4. Impairments of Intelligence, or Learning Disabilities

  5. Memory Impairments

  6. Mental Health Disabilities

  7. Seizure Disorders

Color Blindness

Color blindness is a lack of sensitivity to certain colors. Common forms of color blindness include difficulty distinguishing between red and green, or between yellow and blue. Sometimes color blindness results in the inability to perceive any color.

Conversion Tool

"conversion tool" is any application or application feature (e.g., "Save as HTML") that transforms convent in one format to another format (such as a markup language).

2 Definitions from non-WAI resources


The art of ensuring that, to as large an extent as possible, facilities (such as, for example, Web access) are available to people whether or not they have impairments of one sort or another.

The set of properties that allows a product, service, or facility to be used by people with a wide range of capabilities, either directly or in conjunction with assistive technologies. Although the term "accessibility" typically addresses users who have a disability, the concept is not limited to disability issues.

Access Key(s)

, See also: Mnemonic, See also: Modifier key The portion of an option name or control label used for keyboard selection. Also called mnemonic, implicit designator, or menu mnemonic. See implicit designator.

Modifer key

3 To do's

Verify that terms in this document are actually defined in the documents that we reference. It seems that some of the terms are used by the document but not actually defined there. Check everything before Captions.

4 References

Authoring Tool Accessibility Guidelines 1.0 (See http://www.w3.org/TR/ATAG10/.)
Authoring Tool Accessibility Guidelines 1.0 Techniques (See http://fixthis.org.)
Authoring Tool Accessibility Guidelines Wombat (See http://fixthis.org.)
How People with Disabilities Use the Web (See http://fixthis.org.)
Human Factors and Ergonomics Society (See http://fixthis.org.)
National Cancer Institute (See http://fixthis.org.)
PDF Techniques for WCAG 2.0 (See http://fixthis.org.)
SMIL2.0 (See http://fixthis.org.)
Scalable Vector Graphics 1.0 (See http://www.w3.org/TR/SVG/.)
User Agent Accessibility Guidelines 1.0 (See http://www.w3.org/TR/UAAG10/.)
Web Content Accessibility Guidelines 1.0 (See http://www.w3.org/TR/WCAG10/.)
Web Content Accessibility Guidelines 2.0 (See http://www.w3.org/TR/WCAG20/.)
Core Techniques for WCAG 1.0 (See http://fixthis.org.)
Glossary from "Weaving the Web" by Tim Berners-Lee (See http://www.w3.org/People/Berners-Lee/Weaving/glossary.html.)
XML (See http://fixthis.org.)