We use a table box (via a bbcode) and tell members that they can't use it since it seems no one has been able to (or has the inclination to

) come up with a hack that prevents some usergroups from using some custom bbcodes.
The bbcode we use:
Code:
<table bgcolor=#666699><tr><td bgcolor=#666699><font color=white size=1><b>Posted by {option}:</b></font></td></tr><tr><td bgcolor=white><font color=black size=2>{param}<p></font></td></tr></table>