When I see css.php being called in XF headers it's got a bunch of parameters and what looks like an incrementing id# passed as parameters. Code: <link rel="stylesheet" type="text/css" href="css.php?css=xenforo,form,public&style=7&d=1297095139" /> <link rel="stylesheet" type="text/css" href="css.php?css=attachment_editor,bb_code,editor_ui,likes_summary,message,message_user_info,quick_reply,share_page,thread_view&style=7&d=1297095139" I'm guessing the d=##### is to force the css to be recached when there is an update? Ideally we'd like to rework a WP theme like Sandbox to use XF css classes, and then just call in the xf css directly so that the same file is cached and reused throughout the site. It would give us great semantic markup on the WP side, and make the two sides automatically styled the same while improving the user experience as you'd only cache the .css once. Is there a way to make that happen? TIA for any clarification/assistance anyone can provide!