While looking for the Yum plugins today, I came across this page [url: http://docs.fedoraproject.org/en-US/Fedora_Core/5/html/Software_Management_Guide/sn-yum-managing-plugins.html ]
The last line of the first paragraph is -
The yum project maintains a list of plugins on the page http://wiki.linux.duke.edu/YumPlugins.
 But the link is broken.
I think this is the url that should be hyperlinked. [url: http://yum.baseurl.org/wiki/YumUtils ]

Now here is a question. The Yum plugin page I came across is for FC5. Now, as its an aged version, are the pages related to it, not eligible for updating? I mean once a version is replaced by the newer one, the pages are left as they were? or are they updated still?