diff --git a/index.html b/index.html
index f4fef22d7..307efd345 100644
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+++ b/index.html
@@ -11297,6 +11297,7 @@ <h2>Definitions of States and Properties (all aria-* attributes)</h2>
 				<ul>
 					<li>Comment: <code>aria-details</code> refers to an element with role <rref>comment</rref>.</li>
 					<li>Definition: <code>aria-details</code> is applied to an element with role <rref>term</rref> and refers to an element with role <rref>definition</rref>.</li>
+					<li>Caption: <code>aria-details</code> is applied to an element with role <rref>figure</rref> and refers to an element with role <rref>caption</rref>, or an element within a <code>caption</code>.</li>
 					<li>Footnote: <code>aria-details</code> refers to an element with role <code>doc-footnote</code>. This role is defined in [[DPUB-ARIA-1.0]].</li>
 					<li>Endnote: <code>aria-details</code> refers to an element with role <code>doc-endnote</code>. This role is defined in [[DPUB-ARIA-1.0]].</li>
 					<li>Description or general annotation: <code>aria-details</code> refers to an element with any other role.</li>