Help:Hidden URL field

An anti-spam feature is in use on Wikia is a hidden URL field. Edits which add any content to this hidden field will be rejected on save or the user will be asked to complete a captcha.

Why? Wikia receives many edits from spam bots where a piece of junk text is added to a page and no URL is saved. If the spam bots did try to save a URL, they would be asked to complete a captcha or the edit would be rejected because the URL was on the spam blacklist. If no URL is added, it is harder to block the edit.

We believe the lack of URL may be because the spam bots are designed for blogs. On a blog comment, there are fields for your URL and for your comment. On sites without that URL field, the bots are leaving only the junk comment without any spam links.

The phrase similar to "How r u? nice site!" was blocked across Wikia. Before we blocked it, that text was placed on many pages across the site. To see how it used on blogs and forums, try a search for "How r u? nice site!". On sites other than wikis, the phrase is accompanied by spam links.

By adding a hidden URL field which only spam bots will fill in, we can assume that if that field is filled in, the editor is a spam bot.

Other ways we are dealing with this problem are to block commonly used junk phrases (like "How r u? nice site!") from either the text or the edit summary. However, the spam bots frequently change the phrases they use and sometimes use words that can not be blocked in this way since they are commonly used for genuine reasons (like "Thanks").