added isindex to the list of naughty never allowed tags in xss_clean()
diff --git a/user_guide/changelog.html b/user_guide/changelog.html
index b24b081..8675d71 100644
--- a/user_guide/changelog.html
+++ b/user_guide/changelog.html
@@ -87,6 +87,7 @@
<ul>
<li>Improved performance and accuracy of xss_clean(), including reduction of false positives on image/file tests.</li>
<li>Added a few openxml document mime types, and an additional mobile agent to mimes.php and user_agents.php respectively.</li>
+ <li>Added sanitization in xss_clean() for a deprecated HTML tag that could be abused in user input in Internet Explorer.</li>
</ul>
</li>
</ul>