Control Panel > Registration
Forum Rules set it up, and the link to it will be displayed in your footer.
this is what the user agrees to so they can can proceed with using your forum.
edit: it is the blocks of text that you directly copied from my forum about two months ago when you asked me if i had a problem with you using them. My reply then was, "go ahead. just update them to match your forum." and thats my reply also today
cheers