Glossary
Accessibility terms, defined.
The words used in laws, standards, audits and conformance reports, each in one to three sentences. Every term has its own link, so you can point a colleague straight to it.
Terms, A to Z
A
- Accessible name
- The name assistive technology announces for an element, computed from its text content, its label,
aria-label,aria-labelledbyor the alt text of an image inside it. An icon button with no accessible name is announced only as "button". WCAG 4.1.2 requires one for every control. - ACR (Accessibility Conformance Report)
- A completed VPAT for one product and version. For each criterion it states a conformance level (Supports, Partially Supports, Does Not Support or Not Applicable) with remarks. See ACRs for software vendors.
- ADA Title II
- The part of the Americans with Disabilities Act that covers state and local government. A Department of Justice rule requires their web content and mobile apps to meet WCAG 2.1 AA by 26 April 2027 for entities serving 50,000 people or more, and by 26 April 2028 for smaller entities and special districts.
- ADA Title III
- The part of the Americans with Disabilities Act that covers businesses open to the public. Courts usually treat their websites and apps as covered and take WCAG 2.1 AA as the benchmark. It is enforced mainly through private lawsuits.
- Alt text
- A text alternative for an image, usually in the
altattribute, that conveys what the image shows or does in context. A decorative image takes an emptyalt=""so screen readers skip it. Required by WCAG 1.1.1. - ARIA
- WAI-ARIA, a W3C specification of attributes that give custom components a role, states and properties that assistive technology can read. A native HTML element is preferred wherever one exists, because incorrect ARIA makes a component harder to use, not easier.
- Assistive technology
- Software or hardware that people with disabilities use to operate a computer or phone: screen readers, screen magnifiers, voice control, switch devices and refreshable braille displays.
C
- Conformance
- Meeting every success criterion at a given level for a defined scope. WCAG conformance applies to full pages and complete processes, so one failing step makes a whole checkout non-conformant. Conformance with a standard is a technical finding; legal compliance is decided by courts and regulators.
- Contrast ratio
- The difference in relative luminance between two colours, from 1:1 to 21:1. WCAG 1.4.3 requires at least 4.5:1 for normal text and 3:1 for large text. Suretto calculates it from browser-derived foreground and background colours, with additional analysis for complex visual cases.
- Cyber Resilience Act
- Regulation (EU) 2024/2847, which sets cybersecurity requirements for software and connected products sold in the EU. Vulnerability reporting has applied since 11 September 2026, and the main obligations apply from 11 December 2027. It is not an accessibility law, but it falls on the same product teams.
D
- Demand letter
- A letter from a claimant's lawyer alleging that a website or app is inaccessible and asking for remediation and payment, often before a lawsuit is filed. Under ADA Title III, a letter can end in a settlement or lead to a filed case.
E
- EAA (European Accessibility Act)
- Directive (EU) 2019/882, applied since 28 June 2025 to products and services sold to EU consumers, including e-commerce, consumer banking, telecoms, transport and e-books, wherever the company is based. Service providers with fewer than 10 employees and €2 million or less in turnover are exempt. Its technical standard is EN 301 549.
- EN 301 549
- The European standard for the accessibility of information and communication technology. It covers the web, software, documents and hardware, and its web requirements incorporate WCAG 2.1 AA. An update aligning it to WCAG 2.2 is under way.
F
- Focus order
- The sequence in which keyboard focus moves through a page or screen. WCAG 2.4.3 requires an order that preserves meaning and operation, so a dialog takes focus when it opens and returns it when it closes.
- Focus visible
- A visible indicator on the element that has keyboard focus, required by WCAG 2.4.7. WCAG 2.2 adds 2.4.11, which requires that the focused element is not entirely hidden by other content, such as a sticky header or a cookie banner.
G
- GIGW
- The Guidelines for Indian Government Websites, now in version 3.0, which government websites and apps in India follow. They adopt WCAG as their accessibility baseline.
J
- JAWS
- Job Access With Speech, a commercial screen reader for Windows, widely used at work. Suretto records JAWS runs as part of verification.
K
- Keyboard trap
- A component that keyboard focus can enter but cannot leave, so a keyboard user is stuck. WCAG 2.1.2 forbids it. Common sources are modal dialogs, embedded media players and third-party widgets.
L
- Level A, AA and AAA
- The three conformance levels of WCAG. Level A is the minimum, Level AA is the level that laws and procurement rules point to, and Level AAA is the highest. The W3C does not recommend AAA as a general requirement for whole sites, because some content cannot meet it.
M
- Market surveillance
- The checks national authorities in the EU make on products and services already on the market. Under the EAA they can order corrections and impose fines; Germany's authority has operated since September 2025, with correction orders first and fines up to €100,000.
N
- Non-text contrast
- WCAG 1.4.11, which requires a contrast ratio of at least 3:1 for the visual parts of controls and meaningful graphics against adjacent colours. Input borders, focus indicators, checkbox outlines and chart lines are typical examples.
- NVDA
- NonVisual Desktop Access, a free, open-source screen reader for Windows made by NV Access. Suretto records NVDA runs as part of verification.
O
- Overlay
- A third-party script added to a website that shows an accessibility toolbar and tries to patch defects in the browser at runtime. The source code does not change. In 2025 the US Federal Trade Commission ordered one overlay vendor to pay $1 million over claims that its product made sites compliant.
R
- Reflow
- WCAG 1.4.10, which requires content to be usable at a width of 320 CSS pixels without scrolling in two directions. That is equivalent to a 1280-pixel-wide page zoomed to 400%. Content that needs a two-dimensional layout, such as data tables and maps, is exempt.
- Remediation
- Fixing accessibility defects. At Suretto it means changes to your source code, delivered as pull requests and verified independently, as opposed to patches applied at runtime by an overlay.
- Role
- What kind of element something is (a button, link, checkbox, tab or dialog), exposed to assistive technology by native HTML or by ARIA. WCAG 4.1.2 requires the correct role, together with the accessible name and current state, for every control.
S
- Screen reader
- Software that reads the content of a screen aloud or to a braille display, and lets the user move by headings, links, landmarks and form fields. NVDA, JAWS, VoiceOver and TalkBack are the most common.
- Section 508
- Section 508 of the US Rehabilitation Act, which requires federal agencies to develop, buy and use accessible technology. Its revised standards incorporate WCAG 2.0 AA. Vendors selling to federal agencies are asked for an ACR.
- Success criterion
- A single testable requirement in WCAG, numbered and named, such as 1.4.3 Contrast (Minimum). Each criterion is assigned a level: A, AA or AAA.
T
- TalkBack
- The screen reader built into Android. Suretto tests Android screens with TalkBack for pilot partners.
- Target size
- WCAG 2.5.8, new in WCAG 2.2, which requires pointer targets to be at least 24 by 24 CSS pixels, or spaced so that a 24-pixel circle on each does not overlap another target. Inline links and a few other cases are exempt.
V
- VoiceOver
- The screen reader built into Apple's macOS, iOS and iPadOS. Suretto records VoiceOver runs as part of verification.
W
- WCAG
- The Web Content Accessibility Guidelines, published by the W3C. The current version is 2.2. Its success criteria are grouped under four principles (perceivable, operable, understandable and robust), and WCAG 2.2 Level AA is the standard Suretto tests against.
Laws and dates are summarised from the compliance page, which lists its sources. This glossary is not legal advice.