One of the most interesting things about the site to me was the navigation system. There is an "up" button and a "next" button in the navigation panel on the pa

One of the most interesting things about the site to me was the navigation system. There is an "up" button and a "next" button in the navigation panel on the pages. It is conceptually set up as a file directory--which has been replaced in navigation with the modern convention of "forward" and "back" buttons.