cahva, that's like saying don't use .htaccess files.
Since there's already an entry for those, it should be easy enough to copy it and deny access to the .inc files. The one for .htaccess is like this:
<Files ~ "^\.ht">
Order allow,deny
Deny from all
</Files>
~ ".ht" means:
~ = reg ex match
^ = anchor at beginning of string
. = a dot (you have to escape them with a )
ht = string to match
doing a 'man 7 regex' on rhlinux or 'man regex' on freebsd will get a page on posix regular expressions, the kind apache uses.
Since we want to match the right side against, .inc, we need to right anchor, the $ symbol.
<Files ~ "\.inc$">
Order allow,deny
Deny from all
</Files>
and testing it on my box, it seems to work.
p.s. love the boing icon!