plugin=diff is not implemented.
http://tuotehhou.y.ribbon.to/index.php?%2BCA%2BSoffic%20CA%20%E3%82%B7%E3%82%B9%E3%83%86%E3%83%A0%E5%88%A9%E7%94%A8%E8%A8%B1%E8%AB%BE%E5%A5%91%E7%B4%84%E6%9B%B8
plugin=diff is not implemented.