The wikipedia mobile site has the following html in the footer:
<li id="footer-info-mobile-switcher"><h2><img src="/static/images/mobile/wikipedia-wordmark-en.png" alt="Wikipedia<sup>®</sup>" height="15" width="97" /><sup>®</sup></h2>
With images disabled (on my browser), this creates output like:
Wikipedia<sup>®</sup>®
[The last ® being superscript].
This looks rather silly. There is no ® even in the image. It shouldn't be in the alt text, and definitely shouldn't be there twice.