there sometimes might be a need to only show certain stories to authenticated users only, so here we go. you can only see this node, when logged in as an authenticated user... When you add a node, below you will find the option of "view/Edit Permissions", where you can also state who is allowed to see your node and/or edit.
With this function we can now also ditch the wiki we had and put all the documents as a normal page where only authenticated users can edit... In other words, you can edit this specific post!