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Creating Accessible LibGuides

This guide presents information about how to create and format content in LibGuides to reach as many students as possible, including those using assistive technologies.


This glossary reflects some of the terms in the WCAG 2.2 glossary, along with additional terms to further define the context of the WCAG 2.2 standards. Terms that are not found in the WCAG 2.2 glossary are labelled.

Level A / Level AA / Level AAA

The three levels of conformance. Level A is the lowest level and Level AAA is the highest level. 

Accessibility Supported

Web pages that allow users to successfully access content through assistive technology, along with accessibility features in browsers and other user agents. For more information on what is required to qualify as an accessibility-supported use of a Web content technology, visit the WCAG 2.2  glossary.

Ambiguous to Users in General

Refers to a link that both users with and without disabilities cannot determine the purpose of until the link is activated. 

WCAG example: In the sentence "One of the notable exports is guava", the word guava is a link. The link could lead to a definition of guava, a chart listing the quantity of guava exported or a photograph of people harvesting guava. Until the link is activated, all readers are unsure and the person with a disability is not at any disadvantage.


*Not in glossary*

Also: Accessible Rich Internet Applications

This is a way to add information to HTML so that assistive technology can tell the user what is happening on the page. Types of ARIA tags include navigation landmarks, form hints, and error messages. HTML 5 currently includes more accessibility, so ARIA may not be needed as often.

Assistive Technology

Any hardware or software that helps users with disabilities receive and understand the information in a web page. Examples include screen magnifiers, screen readers, and alternative keyboards.

Audio Description

An audio track that is added to a video's soundtrack to describe the information and action occurring in video.


Also: Completely Automated Public Turing test to tell Computers and Humans Apart

Tests that ask the user to provide information to determine the user is human and not a computer or bot.


Text alternatives that are displayed as a video or audio plays, releasing information at the same time as the media.

Captions are slightly different from subtitles, as captions describe all action including music, sound effects, and locations. Subtitles only show the spoken word equivalent.


The requirements needed to meet the WCAG standards and guidelines.

Contrast Ratio

The ratio between light colours and dark colours (ie. text colour compared to background colour). There needs to be a high enough ratio so individuals with visual disabilities can identify the difference in colour. 

The WCAG uses the equation (L1 + 0.05)/(L2 + 0.05) where L1 is the relative luminance of the lighter colors and L2 is the relative luminance of the darker colors.


The point on the webpage where the user’s input (pointer; mouse; keyboard) interacts with the web page.


*Not in glossary*

The standards created by the WCAG.


*Not in glossary*

When a user focuses their input (pointer; mouse; keyboard) over a piece of information, which causes additional information to appear. 

Human Language

Languages that humans communicate with, as opposed to coding or markup languages

Images of Text

Text that appears in an image or other non-text content; for example: a person's name on a name tag in a photograph. Image of text cannot be read by assistive technology alone so additional code must be added (ie. alternative text). 


Found under "abbreviation" in the WCAG glossary.

Shortened forms of a name or phrase made from the initial letters of words or syllables contained in that name or phrase. Example, “ESP is an initialism for extrasensory perception.”

It is similar to an acronym, but an initialism pronounces the letters separately and not as a word.


*Not in glossary*

Parts of a web page that require users to add information; for example, a street name/postal code on a form.


*Not in glossary*

Logos and icons representing brands or companies are handled different to standard images. Individual criterion that handle logos and icons different than images are clearly labelled.

Non-Text Content

Any content that is not a sequence of characters that can be understood by assistive technology or where the sequence is not expressing something in human language. Example: ASCII art, which is a picture created by a spatial arrangement of characters or glyphs.


Non-live media or information

Relative Luminance

The relative brightness of any point in a colourspace, normalized to 0 for darkest black and 1 for lightest white.

Resize Text

*Not in glossary*

Functions in either a web page or through assistive technology that allows the user to change the text size.

Success Criterion

*Not in glossary*

The requirements of the WCAG needed to fulfill the guidelines for accessibility.

Synchronized Media

Audio or video that is accompanied by alternative texts that highlight relevant information as the media progresses; for example, captions in a video are synchronized media.

Text Alternative

When using audio, video, or images, there is a text option that displays the same content. 

Time-Based Media

*Not in glossary*

Audio or video that releases information over time.


*Not in glossary*

A text version of audio or video content that includes timestamps and other auditory or visual cues.

User Agent

Software that retrieves and presents internet content for users. Includes, web browsers, media players, plug-ins, and other programs - including assistive technologies - that help users retrieve, render, and interact with Web content.

User Interface Components

Also: User Interface Elements

A part of the content that is perceived by users as a single control for a distinct function.


"Copyright © 2020 W3C® (MIT, ERCIM, Keio, Beihang). This software or document includes material copied from or derived from Web Content Accessibility Guidelines (WCAG) 2.2."