Forums such as this one often use vBulletin as their software. vBulletin can make RSS feeds, so for example, you can read the Mobile Read forums at
https://www.mobileread.com/forums/external.php?type=rss2 as an RSS feed.
Now, I can't find a recipe for a Calibre vBulletin forum anywhere, and when I've tried just the most basic steps, the results have been unsatisfactory.
Anyone got any ideas?