The issue: register_globals is still used in many applications and even for developing Pollutes the global namespace. Can overwrite not properly initialized variables. The solution: Turn off register_globals in development and production environments. Workarounds could overwrite global variables before PHP 4.4.1 and PHP 5.0.5 Still possible with own importing mechanisms. Fixed in extract() and import_request_variables(). register_globals and magic_quotes will be removen in PHP 6