A11y Standard

Origin & evolution

WCAG organises its requirements under four principles, captured by the acronym POUR: perceivable, operable, understandable, and robust. Under those sit guidelines, and under the guidelines sit individual success criteria, each tagged with a conformance level of A, AA, or AAA. The levels are cumulative, so AA conformance requires every Level A criterion plus the AA additions. WCAG 2.2 became a W3C Recommendation on 5 October 2023 and was later approved as ISO/IEC 40500:2025.

Standards rarely stay purely technical. Several legal regimes point at WCAG as their reference. The United States Section 508 refresh of 2017 adopted WCAG 2.0 Level AA for federal information and communications technology, and the European EN 301 549 standard references WCAG for the EU market. AA is the level most regulations settle on.

How it works in practice

A fintech team commits to WCAG 2.2 Level AA for its web app. That single declaration expands into roughly fifty individual success criteria the product must satisfy, from keyboard operability to a 4.5:1 text contrast ratio. The team records the target version and level once, then every audit, guideline, and fix traces back to it. When a regulator or enterprise buyer asks "what do you conform to?", the answer is one precise string, not a vague claim of being "accessible".

Accessibility standard vs. its neighbours

• Accessibility guideline: the standard is the whole document and its declared conformance target; a guideline (or success criterion) is one testable rule inside it, such as the contrast minimum. The standard contains many guidelines.
• Accessibility audit: the standard states what must be true; the audit is the act of checking whether it is. One is the ruler, the other is the measurement.
• Compliance requirement⛲Compliance RequirementComplianceA compliance requirementView reference →: a compliance requirement is a legal or contractual obligation that may name a standard, such as a procurement clause demanding WCAG 2.2 AA. The standard is the technical content; the requirement is the obligation to meet it.

In the graph

In the Unified Product Graph, an accessibility standard sits in the quality and operations region as the anchor for accessibility work. A product declares conformance through product_conforms_to_a11y_standardProductconforms toA11y Standardhierarchy, and the standard's individual rules attach via a11y_standard_contains_a11y_guidelineA11y StandardcontainsA11y Guidelinehierarchy. Audits prove conformance with a11y_standard_verified_by_a11y_auditA11y Standardverified byA11y Audithierarchy, and design-time specifications📋SpecificationFoundationsA canonical open standard or specification that primitives and products conform toView reference → connect through a11y_standard_annotated_with_a11y_annotationA11y Standardannotated withA11y Annotationhierarchy. That shape keeps the standard as the single point of reference: change the target version and every connected guideline, audit, and annotation🗯️AnnotationDesign SystemA note or markup on a design artifactView reference → is queryable against it.