it links to the RSS feed of that particular forum
what's and RSS feed i hear you ask , an rss feed makes it possible for people to keep upto date with content in an automated manner that's easier than checking them manually
RSS content can be read using software called a "feed reader" or an "aggregator." The user subscribes to a feed by entering the feed's link into the reader or by clicking an RSS icon in a browser that initiates the subscription process. The reader checks the user's subscribed feeds regularly for new content, downloading any updates that it finds.
one such program that allows you to read rss feeds is a freeware program called http://www.rssreader.com/
hope that helps