diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index fb0a0d14c94bad7532a9c99f8fd2934a18305d5e..6276a615f21a559c973b146403a498139bbcf93d 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -3110,6 +3110,12 @@
             then this setting not required.
           </dd>
         </dl>
+        <p>
+          Note: The <code>managed</code> attribute is only used with PCI devices
+          and is ignored by all the other device types, thus setting
+          <code>managed</code> explicitly with other than PCI device has the same
+          effect as omitting it.
+        </p>
       </dd>
       <dt><code>source</code></dt>
       <dd>The source element describes the device as seen from the host using