Idea: private discussion

Users can create a private discussion. Such discussions will be visible only to the creator. If the user wants to invite discussion of other people, then indicate - @nick @nick2 @nick3... (in the topic).

Discussion displayed will be in the selected category. Everything is as usual. But only for invited users.

Example: http://esotalk.org/forum/
It a similar idea.

What do you think?

psychobunny

It's probably doable via plugin.

This would probably be a good place to start, you'd basically just need to add the invite mechanic to this plugin:

https://github.com/julianlam/nodebb-plugin-support-forum