This screen in the Chat Room wizard allows you to specify who will NOT be allowed to use the current chat room.
To add a new blocked user, click New. CNAV will display the Chooser. Use the Chooser to add any new groups or individuals (members) as users banned from this chat room, then click Submit. (Provision of a Blocked Users function allows you to enter a large group as chat room users, then block usage by one or two individuals within that group. This allows you to remove troublesome users without losing the convenience of making the chat room available to a large group.)
To remove blocked users (allowing those users to now access this chat room), tick the appropriate Delete checkboxes and click Delete Selected.
After making all desired changes, click the right-pointing arrow to commit your changes. CNAV redisplays the list of available chat rooms.