access control

Hi teanm,

I can see there is access control. - is ACL only for displaying link in article?
or does it also prevent from direct access to a file?
what i mean is if there is article for registered users only - does the download link contains direct link to article like:
http://www.mysite.com/files/showroom.pdf ?

I would need that only registered users have access to such file (even without link), as if someone sends out a link or search engines discover links, files would be publicly available.
And I want otherwise so that files are only available to registered users and even if someone paces link:
http://www.mysite.com/files/showroom.pdf
or the file is unavailble, or ppl are asked to login.

thank you for your answer.

Best regards
Vladimir