diff --git a/FAQ.md b/FAQ.md
index 87385be747..b0ed4583bc 100644
--- a/FAQ.md
+++ b/FAQ.md
@@ -2955,6 +2955,7 @@ The following extra functions are available:
 * *Size(array)* (returns the number of items in an array; since version 1.2179)
 * *knownContact()* (returns a boolean indicating that the from/reply-to address is in the Android address book or in the local contacts database)
 * *AI(prompt)* (perform interference with the configured AI model using the specified prompt, returning the result as a string; since version 1.2243)
+* *Is(flag)* (flag is one of seen, answered, flagged, deleted; to check if a message is read (seen), starred (flagged), etc.; since version 1.2277)
 
 Example conditions:
 
diff --git a/index.html b/index.html
index 9e66935307..578329df63 100644
--- a/index.html
+++ b/index.html
@@ -1630,6 +1630,7 @@ X-Google-Original-From: Somebody &lt;somebody+extra@example.org&gt;</code></pre>
 <li><em>Size(array)</em> (returns the number of items in an array; since version 1.2179)</li>
 <li><em>knownContact()</em> (returns a boolean indicating that the from/reply-to address is in the Android address book or in the local contacts database)</li>
 <li><em>AI(prompt)</em> (perform interference with the configured AI model using the specified prompt, returning the result as a string; since version 1.2243)</li>
+<li><em>Is(flag)</em> (flag is one of seen, answered, flagged, deleted; to check if a message is read (seen), starred (flagged), etc.; since version 1.2277)</li>
 </ul>
 <p>Example conditions:</p>
 <p><code>header("X-Mailer") contains "Open-Xchange" &amp;&amp; from matches ".*service@.*"</code></p>