I'm an ASP guy, but I rooted around for a PHP equivalent of some code I use, and found this: <? //Set no caching header("Expires: Mon, 26 Jul 1997 05:00:00 GMT"); header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT"); header("Cache-Control: no-store, no-cache, must-revalidate"); header("Cache-Control: post-check=0, pre-check=0", false); header("Pragma: no-cache"); ?> Placed at the top of a page, it's supposed to prevent caching - for what it's worth. From what I gather from my admittedly minimal research, PHP is supposed to send a "no cache" command to the browser automatically, but it couldn't hurt to specify. I guess I should break out a PHP for Dummies book and edumacate myself some more.