No, PHP_SELF, da documentazione, dovrebbe contenere il nome dello script php corrente:
http://php.net/manual/it/reserved.variables.server.php
The filename of the currently executing script, relative to the document root. For instance,$_SERVER['PHP_SELF'] in a script at the address http://example.com/foo/bar.php would be /foo/bar.php. The __FILE__ constant contains the full path and filename of the current (i.e. included) file. If PHP is running as a command-line processor this variable contains the script name since PHP 4.3.0. Previously it was not available
In ogni caso io ne sconsiglio l'utilizzo, perché con mod_rewrite, non sempre funziona come dovrebbe.