When browsing the manual I noticed that SERVER_ADDR, part of the $_SERVER/$HTTP_SERVER_VARS, is not listed on http://www.php.net/reserved.variables. I don't know if it is supposed to be like this... but it would seem sensable to me to have this variable listed on that page with the rest. I notice that not all of the variables in $_SERVER are not on that page, so I'm assuming this was done by design. Another one that I've noticed is SCRIPT_URI which only shows up when RewriteEngine is on. I personally think these should be documentated to save confusion, instead of just supprises to find later on when looking in a phpinfo() page.