There's some bug in site rendering that lets it mismatch tags
(<p><small></p></small>), which makes the page invalid XML, so it
can't be used to do AJAX-type things. This was making all edit pages
invalid XHTML on Commons because of a bug in the edittools box. See:
> Omegatron wrote:
> > I thought the rendered HTML was passed through a validator/cleaner
> > program after rendering? Maybe this isn't used on things in the
> > Mediawiki: namespace?
> Tidy has been disabled for UI message display for performance reasons.
> -- brion vibber (brion @ pobox.com)