Last modified: 2013-06-08 14:29:26 UTC
Sanitizer lets out <br clear="both" /> <br clear="both" /> makes the page invalid ( http://www.w3.org/TR/xhtml1/dtds.html#dtdentry_xhtml1-transitional.dtd_br ), the result should be either <br style="clear: both;" /> or <br clear="all" />
Sanitizer doesn't currently validate the contents of attributes which have value restrictions in the DTD.
Marking as WONTFIX. We don't support XHTML 1.0 and DTDs are irrelevant now. Backing out of support for deprecated/removed attributes is bug 24529.