Re: Multiple-level forums
Exact, you just need to check the is category when creating (or modifying) the forum.
You also have to check the theme. Kakumei is ok, but some others display 0 (zero) in front of the father forum, this is disturbing for users who fail to understand that the top forum is only a container and not a real forum. Some doesn’t display forum as a hierarchy (with a father / container forum and sub forums).