Hierarchical Categories?

Hello,
Love your great project and so wish to move on from archaic phpBB but not sure I can yet.

When you @codinghorror write: We don’t have any plans to implement categories beyond parent and child, that is, 1 level of subcategories"? Does this mean I can or cannot do what I need for my private communities with forums where we need :

  • 1 Public common help Forum for all users of all groups (L1?)
    ++ with topics (L2?)
    +++ and messages (L3?)

  • +1 Private Forum (L1?) for each and every group and only visible to the members of each group,
    ++ each with 4 sub-forums (L2?), each only visible to the members of 4 sub-groups in that group,
    +++ each with topics (L3?)
    ++++ and messages (L4?).
    Knowing that a member of one group can be a member of another group.
    And that a member of one sub-group can be a member of many sub-groups in its group, or just one.

I know it seems a little complicated but I promise that the use is basic. It just helps totally different small hierarchical communities to have their own private board system, where someone can sometimes be in several of them. And experience showed it is much easier to manage than multiple installs and replications of a dedicated forum engine for each group.

If your amazingly promising code can’t seem to do that now or in the future and you have anything to recommend… Thanks a lot for your lights.