Plesk 6 special config in vhost.conf files
In Plesk 6.0 you can create a vhost.conf files in the virtualhosts domain directory to configure some special Apache directive:
1- create the vhost.conf files in /home/httpd/vhosts/mydomain.com/conf/vhost.conf
2- run /usr/local/psa/admin/bin/my_apci_rst which will force Plesk to discover its existence and bind it into the httpd.include.
3- restart Apache for the changes to take effect.