Glossary
Every abbreviation on this site, expanded
Accessibility runs on initials, and a page that assumes you know them all is written for people who already agree with it.
This page is how the site meets WCAG 3.1.4. It is linked from the footer of every page, and a test fails if a page starts using an abbreviation that is not defined here.
- AA
WCAG conformance level AA - The middle of the three levels, and the one most accessibility legislation references.
- AAA
WCAG conformance level AAA - The highest level. WCAG itself does not recommend it as a general policy, because some AAA criteria cannot be satisfied for all content — which is why it is opt-in here rather than the default.
- AI
Artificial intelligence - API
Application programming interface - CDN
Content delivery network - DOM
Document Object Model - The browser's live representation of a page, as opposed to the HTML that was sent.
- DSAR
Data subject access request - A request from a person to see what data you hold about them, under the GDPR.
- EAA
European Accessibility Act - Directive (EU) 2019/882, applicable since 28 June 2025.
- EEA
European Economic Area - EN
European Norm - The prefix on a European standard. EN 301 549 is the accessibility one, and it is what the EAA is assessed against in practice.
- EU
European Union - GBP
Pound sterling - By its ISO 4217 currency code.
- GDPR
General Data Protection Regulation - HTML
HyperText Markup Language - IAB
Interactive Advertising Bureau - ISO
International Organization for Standardization - ISO 4217 is the currency-code standard; ISO 8601 is the date one.
- ICO
Information Commissioner's Office - The United Kingdom's data protection regulator.
- JSON
JavaScript Object Notation - OCR
Optical character recognition - SARIF
Static Analysis Results Interchange Format - An OASIS standard for reporting static analysis results. It is the format code hosts read to show findings against the lines of a pull request.
- OASIS
Organization for the Advancement of Structured Information Standards - The body that publishes SARIF.
- SDK
Software development kit - TCF
Transparency and Consent Framework - The IAB's specification for passing consent signals to advertising vendors.
- UI
User interface - UK
United Kingdom - URL
Uniform Resource Locator - UTC
Coordinated Universal Time - VAT
Value added tax - W3C
World Wide Web Consortium - The body that publishes WCAG.
- WCAG
Web Content Accessibility Guidelines - The W3C standard this product measures against. WCAG 2.2 is current and includes every 2.0 and 2.1 criterion.