goodroi - 2:34 pm on Jan 15, 2009 (gmt 0)

I do not know about mediawiki but I do know that robots.txt can not apply nofollow to links. Robots.txt is a voluntary protocol that helps webmasters tell robots which files and folders should be accessed and which should not be accessed. If you block a file using robots.txt the search engine bots will not access it so they will not see the individual robots meta tag.