Here are feeds that you can currently use on the forums:
Board-wide feed = Feed with 10 most recent posts from all topics in all forums.
URL = feed.php
New topics feed = Board wide feed with the first post of 15 most recent topics in all forums.
URL = feed.php?mode=topics
Active topics feed = Feed that shows 15 last posts, not older then 7 days, for forums that have "Display active topics" enabled.
URL = feed.php?mode=topics_active
News feed = Feed that shows first post of the topics in selected forums.
URL = feed.php?mode=news
Forums feed = Feed that shows a list of all forum titles (not the contents), excluded those forums you have no access to, but including passworded forums (not considered as bug).
URL = feed.php?mode=forums
For forum or topic specific feeds use the following:
Per-forum feeds = Feed with 10 most recent posts from all topics in the selected forum.
URL = feed.php?f=[ForumID]
Per-topic feeds = Feed with 10 most recent posts from the selected topic.
URL = feed.php?f=[ForumID]&t=[TopicID]
[ForumID] and [TopicID] can be found by hovering over a thread/forum.
We are currently looking into an easier way to subscribe to forum/thread feeds.