Ability to hide threads from non-clan members.

[Paratrooper]

Hide content of threads from non-clan members? I really don't know how to elaborate, but this basically means that in your clan's forum section, mods can toggle specific threads so that only clan members can reply to and read what's inside the thread.

[TheGrandmaster]

Many clans have passworded sections, you can apply for one in the Apply/Amend section.

[mikuli]

The good thing about a private subsection within a clan subsection is that it's both passworded and completely invisible to everyone else but the members of the clan and the forum staff, so it's kind-of double protected.