+ An element with a contextual role is one whose computed role semantics are based on its ancestral accessibility tree relationship to + another element or elements. Or, an element whose computed role is dependent upon whether it has other associated accessibility information, such as an author-provided accessible name. +
++ For instance, an element that is an accessibility child of its required accessibility parent would expose a computed role for its given context, + such as a list item (`li` element) within an unordered list (`ul` element). However, the same element might be used within a different markup pattern and could therefore expose + different contextually-dependent computed roles, such as a `section` element with an author-provided accessible name (role `region`) versus an unnamed `section` element (role `generic`). +
++ When the conditions for an element's contextual role are not met, it will commonly expose a computed role of `generic` or with a minimum role, if applicable. +
+Previously, the concept of a contextual role was loosely referred to as an element's "scoped" relationship to another element.
+
+ A li element has an implicit WAI-ARIA role mapping of listitem only when the element is an accessibility child of a
+ menu, ol or ul element that has not had its `list` role mapping suppressed.
+
<ul>
+ <li>...</li> <!-- computed role `listitem` -->
+ </ul>
+ <article>
+ ...
+ <li>...</li> <!-- computed role `generic`, not `listitem` -->
+ ...
+ An aside element has an implicit WAI-ARIA role mapping of complementary only when the element is an accessibility child of
+ the body or main elements, or if the aside has been provided an accessible name.
+
<body>
+ ...
+ <main>
+ ...
+ <article>
+ <aside>...</aside> <!-- computed role `generic`, not `complementary` -->
+ ...
+ <aside aria-label=named>...</aside> <!-- computed role `complementary` -->
+ </article>
+ ...
+ <aside>...</aside> <!-- computed role `complementary` -->
+ </main>
+ <aside>...</aside> <!-- computed role `complementary` -->
+ ...
+ <footer>
+ ...
+ <aside>...</aside> <!-- computed role `generic`, not `complementary` -->
+ </footer>
+...A section element has an implicit WAI-ARIA role mapping of region only when the element is provided an accessible name.
<section title="accessible name">...</section> <!-- computed role `region` -->
+...
+<section aria-label="accessible name">...</section> <!-- computed role `region` -->
+...
+<section>...</section> <!-- computed role `generic`, not `region` -->