HTML tidy filter
From MoodleDocs
This filter checks whether HTML code is XHTML compliant, tidying where necessary. To make this filter work you need to have PHP compiled with the libtidy option; see http://www.php.net/tidy.
Note: You are currently viewing documentation for Moodle 3.3. Up-to-date documentation for the latest stable version of Moodle is probably available here: HTML tidy filter.
