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Accessibility terms and notation, decoded

Quick answer

Most of it is shorthand. "a11y" means accessibility, "WCAG 2.2 AA" names a standard, a version and a level, and a number like 1.4.3 points to one requirement. The lists below define the terms you will meet in an audit report or a demand letter.

Facts last checked

Reading the notation

a11y is short for "accessibility"
First letter
a
Letters in between
11
Last letter
y
A standard, its version and a level
Standard
WCAG
Version
2.2
Level
AA
A success criterion reference
Principle
1
Guideline
.4
Criterion
.3
Level
(AA)
Abbreviations you will see
Short formStands for
WCAGWeb Content Accessibility Guidelines
SCSuccess criterion
WAIWeb Accessibility Initiative, the part of W3C that develops WCAG
ARIAAccessible Rich Internet Applications
ATAssistive technology
VPATVoluntary Product Accessibility Template
ACRAccessibility Conformance Report
ADAAmericans with Disabilities Act
EAAEuropean Accessibility Act

Standards and levels

WCAG
Web Content Accessibility Guidelines. The international standard from W3C that explains how to make web content more accessible to people with disabilities.
Success criterion
One testable requirement in WCAG, such as 1.4.3 Contrast (Minimum). Pages are tested against the success criteria.
Level A, AA and AAA
The three levels of WCAG. A is the lowest and AAA is the highest. Meeting Level AA means meeting every Level A and every Level AA success criterion.
Conformance
Meeting all the requirements of a standard such as WCAG. WCAG judges it for a full page, and for a complete process such as every step of a checkout.
WAI-ARIA
Often just ARIA. A W3C standard of code attributes that tell assistive technology what a custom control is and what state it is in.

How a page talks to assistive technology

A screen reader reads a page's code, not its looks. These terms describe what the code tells it.

Assistive technology
Hardware or software that gives people with disabilities functions a standard browser doesn't offer. Screen readers, screen magnifiers, speech recognition and alternative keyboards are examples.
Screen reader
Software that turns a page into speech or braille, including text you can't see, such as image descriptions. People who are blind use one to read a page.
Accessible name
The name of a button, link or field that assistive technology announces. It can come from text you can see, like the words on a button, or text you can't, like the description of an icon.
Role
What a thing is: a button, a link, a checkbox. Software reads the role to tell people what they have landed on.
State
A property of a control that changes as people use it, such as checked, expanded, selected or disabled.
Landmark
A region of a page that people may want to jump straight to, such as the navigation, the search or the main content.
Alt text
Short for alternative text. Text attached to an image that describes the information or function the image carries. Decorative images get an empty alt.
Focus
The one control that will take what you type or press next. Pressing Tab moves it to the next control.
Focus indicator
The visible change, often an outline, that shows which control has focus. Criterion 2.4.7 Focus Visible (AA) asks for one.
Keyboard trap
A spot where keyboard focus goes in and can't get out by keyboard. Criterion 2.1.2 No Keyboard Trap (A) covers it.
Skip link
A link at the top of a page that jumps straight to the main content. It is one way to meet 2.4.1 Bypass Blocks (A).

Testing and reports

Audit
A structured test of a site against a standard, with a written report of the barriers found. Ours test against WCAG 2.2 Level AA.
Automated scan
A software check of a page's code for errors a program can detect, such as an image with no alt text. In our audits, a person checks what the scan flags.
Manual testing
Testing done by a person, who uses the site with a keyboard and a screen reader and checks each requirement by hand.
User journey
The steps a visitor takes to get something done, such as booking a visit or checking out. WCAG's closest term is a process, and it asks every page in one to meet the level claimed, or a higher one.
Remediation
Fixing the barriers that testing found, in the site's code, design or content.
Retest
Testing again after fixes are made, to check whether each fix worked.
Accessibility statement
A public page about the accessibility of a site. W3C says it should give a commitment to accessibility, the standard applied, such as WCAG 2.2, and contact details for reporting problems.
VPAT
Voluntary Product Accessibility Template. A free blank form from the Information Technology Industry Council (ITI) for reporting how a product meets accessibility standards.
ACR
Accessibility Conformance Report. A VPAT that has been filled in for one specific product.
Overlay
A third-party script added to a site that aims to improve accessibility. The Overlay Fact Sheet, a statement signed by accessibility practitioners, says its changes are applied when the page loads in the visitor's browser.

Laws you will see named

Laws, standards and one legal term. Each law entry says who it covers and which WCAG version it points to, if any.

ADA Title II
The part of the Americans with Disabilities Act that applies to state and local governments. Its web rule names WCAG 2.1 Level A and AA.
ADA Title III
The part of the ADA that applies to businesses open to the public. Its regulation names no WCAG version. The Department of Justice says its reading of the ADA's general requirements applies to web accessibility.
Section 504
Section 504 of the Rehabilitation Act of 1973. It bars disability discrimination in any program that receives federal funding. The HHS web rule under it covers organizations that receive HHS funding and names WCAG 2.1 Level A and AA.
Section 508
Section 508 of the Rehabilitation Act. Technology that U.S. federal agencies buy, build, maintain or use has to meet standards that include WCAG 2.0 Level A and AA.
EAA
European Accessibility Act, an EU directive. Since June 28, 2025 it applies to listed products and services sold to consumers in the EU, including online shopping. It names no WCAG version.
EN 301 549
The European standard for accessible technology products and services. Its 2021 version uses WCAG 2.1 Level AA, and its 2026 version uses WCAG 2.2 Level AA. The 2021 version was still the EU's reference version as of September 2026.
Demand letter
A letter, usually written by an attorney for a client, that sets out a dispute and demands that the recipient take or stop an action. That is the general legal meaning. Your attorney decides how to respond to one.

Sources

  1. The A11Y Project, About (accessed 2026)
  2. W3C, Web Content Accessibility Guidelines (WCAG) 2.2 (2024)
  3. W3C WAI, WCAG 2 Overview (2026)
  4. W3C WAI, WAI-ARIA Overview (2025)
  5. W3C, Accessible Rich Internet Applications (WAI-ARIA) 1.2 (2023)
  6. W3C WAI, Images Tutorial (accessed 2026)
  7. W3C, Technique G1: Adding a link at the top of each page that goes directly to the main content area (accessed 2026)
  8. W3C WAI, Developing an Accessibility Statement (accessed 2026)
  9. Information Technology Industry Council (ITI), VPAT (2025)
  10. U.S. Department of Justice, Guidance on Web Accessibility and the ADA (2022)
  11. eCFR, 28 CFR 35.200: ADA Title II web and mobile app rule (2026)
  12. eCFR, 45 CFR 84.84: HHS Section 504 web and mobile app rule (2026)
  13. Section508.gov, Request Accessibility Information (accessed 2026)
  14. U.S. Access Board, ICT Standards and Guidelines (Revised 508 Standards) (2017)
  15. EUR-Lex, Directive (EU) 2019/882, the European Accessibility Act (2019)
  16. ETSI, CEN and CENELEC, EN 301 549 V3.2.1 (2021)
  17. ETSI, CEN and CENELEC, EN 301 549 V4.1.1 (2026)
  18. Cornell Law School, Legal Information Institute: demand letter (2022)
  19. Overlay Fact Sheet (accessed 2026)
  20. Rehabilitation Act of 1973, Section 504 (87 Stat. 355) (1973)
  21. AccessibleEU (European Commission), notice on the EN 301 549 update (2026)

We provide technical accessibility services, not legal advice.

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