(PHP 4 >= 4.0.4, PHP 5, PHP 7) HTTP response headers

(PHP 4 >= 4.1.0, PHP 5, PHP 7) HTTP Request variables

(PHP 4 >= 4.1.0, PHP 5, PHP 7) Session variables

(PHP 4 >= 4.1.0, PHP 5, PHP 7) HTTP File Upload variables

(PHP 4, PHP 5, PHP 7) The number of arguments passed to script

(PHP 4, PHP 5, PHP 7) References all variables available in global scope

(PHP 4, PHP 5) Raw POST data

(PHP 4 >= 4.1.0, PHP 5, PHP 7) HTTP Cookies An

(PHP 4 >= 4.1.0, PHP 5, PHP 7) Server and execution environment information

(PHP 4 >= 4.1.0, PHP 5, PHP 7) HTTP GET variables