The European Union requires its member states to abide by Web Content Accessibility Guidelines 2.1 (WCAG 2.1) Level AA standards.
Visit [https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=COM%3A2015%3A0615%3AFIN EUR-lex (Directive of the European Parliament and of the Council)].
===EU Web Accessibility Directive===