[_ck_]

You mean not list them in the main list?

(not actually completely hide them)

The same approach should work in 1.0 as 0.9

I showed the exact code to do it in a topic around here somewhere.

Hiding subforms on your home page

https://bbpress.org/forums/topic/hiding-subforums-subforums-from-subforum-pages#post-17436