This update highlights several new template events introduced in phpBB version 3.3.12. Key changes include new hooks for the notifications dropdown and various parts of the UCP (User Control Panel), such as adding optional elements before and after the notification options tab content. Notably, there are no new PHP or ACP template events in this release. These changes provide additional customization options for users.

via (https://www.phpbb.com/community/viewtopic.php?p=16014595#p16014595)