Design Nomenclature / Systems & Spec
WCAG
Also called Web Content Accessibility Guidelines, WCAG 2.2, WCAG 2.1, W3C accessibility guidelines
This entry has not been translated yet and is shown in English.
The W3C's Web Content Accessibility Guidelines: testable success criteria filed under four principles and graded A, AA, or AAA. Conformance is claimed per page, against a stated version, and each level subsumes the ones below. It measures conformance — not whether disabled people can actually complete the task.
In practice
Law by proxy: Section 508 and EN 301 549 both incorporate WCAG 2.x Level AA by reference, which is where most of its legal force comes from.
Not to be confused with
- Level AAThe middle WCAG conformance level, and the one policy nearly always specifies. Requires every Level A and Level AA criterion: text contrast 4.5:1, or 3:1 for large text — 18.66px bold or 24px regular; non-text contrast 3:1; reflow to 320 CSS px; and, from 2.2, target size 24×24 CSS px.
- APCAA contrast model developed for WCAG 3 that reports a polarity-aware lightness contrast value, Lc, rather than a ratio, and factors in text size and weight. It exists because WCAG 2.x contrast handles dark backgrounds poorly. It is a candidate in a working draft — nothing conforms to APCA, and it replaces no shipped criterion.