Update focus-appearance-minimum.html

understanding/22/focus-appearance-minimum.html

@@ -38,9 +38,10 @@ <h2>Focus Appearance (Minimum) Success Criterion text</h2>
                         <li>Has a contrast ratio of at least 3:1 against adjacent non-focus-indicator colors, or is no thinner than 2 CSS pixels.</li>
                     </ul>
                 </li>
+                <li>Where a user interface component has active sub-components, if a sub-component receives a focus indicator, these requirements are applied to the sub-component instead.</li>
             </ul>
 
-            <p>Where a user interface component has active sub-components (for example, an opened drop-down menu shows a list of menu items), if the focus indicator is applied to the sub-component then these requirements can be applied to the sub-components instead.</p>
+            <p class="note">An example of sub-components that may receive a focus indicator are menu items in an opened drop-down menu. However, it may also possible to indicate user interaction for such sub-components relying strictly on a visual indication of which is selected. Where selectable sub-components have no differentiated focus indicator, the visual indicator for sub-component selection is measured against <a href="https://www.w3.org/WAI/WCAG22/Understanding/non-text-contrast.html">1.4.11 Non-text Contrast</a> requirements, not against this Criterion.</p>
             <p class="note">Note: Contrast calculations can be based on colors defined within the technology (such as HTML, CSS and SVG). Pixels modified by user agent resolution enhancements and anti-aliasing can be ignored.</p>
             <dl>
             <dt class="new"><dfn>Focus indicator</dfn></dt>