one of my client wanna install prestashops.

They want register globals off and session autostart setting to off.

Those setting only applied to their store only, not affect whole setting.

Because I have setting to httpd.conf I just add two lines :

<VirtualHost 222.124.140.27 >
ServerAdmin webmaster@clientdomain.com
DocumentRoot /home/clientname/public_html/store
ServerName store.clientname.com
php_flag register_globals off
php_value session.auto_start 0
</VirtualHost>

Yes, master value leave intact and this setting only available to store.clientname.com

To verifiy it you can use phpinfo().