Web sites that accept postings from the public, like this wiki, are often abused by spammers who use automated tools to post their links to many sites. While these spam links can be removed, they are a significant nuisance.
Sometimes, especially when adding new web links to a page, the wiki may show you an image of colored or distorted text and ask you to type the words shown. Since this is a task that's hard to automate, it will allow most real humans to make their posts while stopping most spammers and other robotic attackers.
Unfortunately this may inconvenience users with limited vision or using text-based or speech-based browsers. At the moment we do not have an audio alternative available. Please contact the site administrators for assistance if this is unexpectedly preventing you from making legitimate posts.
Read more at Wikipedia about Captcha.
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