Allows an administrator to ban certain words from comments. This can be a very simple but effective way of stopping spam; just add "viagra", "porn", etc to the banned words list. <p>Regex bans are also supported, allowing more complicated bans like <code>/http:.*\.cn\//</code> to block links to chinese websites, or <code>/.*?http.*?http.*?http.*?http.*?/</code> to block comments with four (or more) links in. <p>Note that for non-regex matches, only whole words are matched, eg banning "sex" would block the comment "get free sex call this number", but allow "This is a photo of Bob from Essex"