I have been asked about the no underline a couple of times. I discovered the technique several years ago quite by accident at the time. That was 7-8 years ago when John had upgraded the FR software. At first I thought it was a fluke.
But upon reading the source code of FR I quickly discovered why it worked. It has to do with the way FR handles the divisions tags. To "read the source code" use "view source" in Internet Explorer or "page source" in FireFox.
I have used the technique a few times over the years. It is really nothing more than a "novelty". It probably shouldn't be used too much in making posts. IMHO