Functional tags are a number of tags that can be added to a WordPress post to achieve different functionality as described below.
featured Adds the article to the list of featured articles on the front page template.
bb-code Renders BB Code in the article.
Notice for bb-code: This disables rendering of WordPress shortcodes and HTML.
redirect-xf Redirects the user to the linked XenForo thread, when the WordPress post is opened.
redirect-wp Redirects the user to the linked WordPress article, when the XenForo thread is opened.