Forum TABLE in the database is all blank,just seems not working at all!

I hadn't noticed the "forum" table before. A strange table. It seems to be empty even if the forum works correctly.

Here is a discussion I found:
http://drupal.org/node/231691#comment-762284

I tried to move a post to a different forum and selected to "leave a shadow copy" and only then an entry was added to the "forum" table.

Now
- The "term_node" table contains the node 2 times, one with the old forum tid and one with the new forum tid
- The "forum" table contains the node 1 time, with the new forum tid
- In the old forum I see "This topic has been moved"
- In the new forum I see the node.

So, the logic seems to work like this: If a node revision exist many times in the "term_node" table, only the one which also exists in the "forum" table and has the same tid is valid. The different tids are shadows.

Probably this could have been designed better. For example, they could have renamed the "forum" table to "forum_I_have_shadows" ;-)

------- Edited to add:

I found that the "forum" table has also another similar use. If you allow "stories" to the Forums vocabulary and you add a story to a forum by selecting a forum term (obviously the story can be tagged with many other terms), then an entry for the story is automatically added to the "forum" table.