I assume you're looking at the toprow function? (http://github.com/nex3/arc/blob/f311b3879c/lib/news.arc#L618) If the url is at /about all you have to do is add:

  (link "about")

To create /about, use newsop. Here's a simple example to append to news.arc:

  (newsop about ()
    (shortpage user nil "about" "About" nil
      (pr "hihihi")))

---

If it works, you might notice that the "about" link on the top nav of the about page isn't highlighted like say the "new" link is for the corresponding page. To fix this, add "about" to toplabels, and change the call in toprow to this:

  (toplink "about" "about" label)