Compliance to these criteria is measured in three levels: A, AA, or AAA. There are testable success criteria for each guideline. WCAG 2.0 contains 12 guidelines organized under 4 principles: Perceivable, Operable, Understandable, and Robust (POUR for short). This certifies it as a stable and referenceable technical standard.
WCAG 2.0 is also an international standard, ISO 40500. This website adopts the Web Content Accessibility Guidelines (WCAG 2.0) as the accessibility standard for all its related web development and services.
