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

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

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

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

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

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

(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) Server and execution environment information

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