Allows restricting the preview search interface to authenticated users only.
Can be set in: profile.cfg, collection.cfg
This option allows the preview side of a profile to only be accessible from authenticated users which have access to the collection and profile.
Note that if set in a profile, it is the value in the 'preview' profile which applies in this case rather than any published value.
By default unauthenticated users may view the preview view of profiles.