So I've noticed a sort of increase in the number of potentially rule breaking signatures as of recent, and I think I may now know why. When you go to the page to edit your signature there's the following line:
While this is technically true, it should really mention rule 12 here (12. Locations shouldn't be obscenely long (they stretch out the edge of the page), and signatures must not be greater than 500 pixels in length and/or 200 pixels in height.) Otherwise the user might get the impression that they can put really large images of Rihanna in their signature or something.
Your signature may contain:
• Any number images
• Images of any size
• Any number of URLs
• Any number of lines
Thanks to Dinny for pointing this out.