st">requirement on page lists</a> or <a href="https://www.w3.org/TR/epub-a11y-11/#sec-mo-order">reading order</a>. Through those constraints the document defines accessibility <a href="https://www.w3.org/TR/epub-a11y-11/#sec-conf-reporting-pub">conformance requirements</a> on top of the conformance levels defined by <a href="https://www.w3.org/TR/WCAG21/">WCAG</a>.
                    </p>
                </li>
                <li>
                    <p>
                      Vocabulary items which serve a