In the Beginner's Class of HTML 101, one of the plethora of 'things' one is taught is Tagging. You can tag a 'location' on a page. To see what I mean, do the following:
1. Set your cursor over the URL POST A NEW MESSAGE. 2. Take a look-see at the BOTTOM-most part of your browser and you'll see: http://www.renovateyourworld.com/wwwboard/wwwboard.htm#post
The #post part of the 'link' is a tag. On the main Forum page, as well as any OTHER WEB page, when you see this type of notation, it means to: Jump to the (stated) tag for the URL.
Now, to make things more complicated, you can click on a tag that's linked to a totally DIFFERENT WEB page. In this case, it will simply load the (stated) WEB page and immediately JUMP to that tag. For our purposes, it happens that the tag is on the SAME page as the Main Forum Page.
So there ya have it! If I confused ya, just let me know and I'll see if I can find a WEB page that describes TAGs. My best to ya and hope this helps.