You can create groups to restrict access to content.
To create groups...
- Go to Your Account > Readers.
- Click on Groups.
- Click on Add Group.
- Specify the Group Name.
- Click Create Group.
From this screen you can also...
- Rename a group by clicking on the little wrench icon to the right
- Delete a group using the red x icon, and
- Reorder the way groups appear in the editor using the up arrow icon.
Your groups will appear in the editor for categories and articles, allowing you to restrict the content to this groups.