Custom phpmyadmin config

There is something i dont get at the following page

http://help.directadmin.com/item.php?id=365

I want to add line

but now i like to know if i must add this line in /var/www/html/phpmyadmin/config.inc.php and then copy it to the custom dir for future updates.

or just make a empty file and place only the one line in it and when da updates it it adds the lines to the config file already there

You need to add the line to the current phpmyadmin config file in /var/www/html/phpmyadmin then copy that file in the specified path for use that on future phpmyadmin updates.

Regards