Mr Limo, thanks for the suggestion, but it doesn't work.
If you view the page source for say, the United forum, you see, right at the top:
<HEAD><TITLE>FlyerTalk Miles</title>
and not, 'FlyerTalk Miles - United' or some such.
Netscape names it's bookmarks according to what is within these title tags. It doesn't matter how you get there in the first place.
If I try to bookmark a thread, it bookmarks with the thread title, but I don't ever bookmark threads.