If you have bought (or transferred) investments onto rplan, then you can setup a private group.
In a private group, only people that you invite to be members can view, post and comment on the posts.
You can invite people by typing in their email address. If the people that you invite aren't already rplan users then they will be prompted to register when they accept your invite.
You will be notified every time somebody posts or comments on a post in the group.