Exchange Calendar Settings

I am trying to understand how Calendar settings work in Exchange, but they are still black out for me.
Microsoft has done some explanation here, but cannot get grasp of it:

any help will be very much appreciated.

Thanks

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Enable the Calendar attendant   Select this check box to enable the Calendar Attendant or clear the check box to disable it. It is enabled by default. When Calendar Attendant is enabled, the following settings are made available:
Remove meeting forward notifications to the Deleted Items folder   If you select this check box, meeting forwarding notifications are moved to the Deleted Items folder after they are processed by the Calendar Attendant. This setting is disabled by default.
Remove old meeting requests and responses   If you select this check box, the Calendar Attendant removes old and redundant updates and responses. This setting is enabled by default.
Mark new meeting requests as Tentative   If you select this check box, incoming meeting requests are marked as "Tentative" on the calendar. If you don't select this check box, pending requests are marked as "Free". This setting is enabled by default.
Process meeting requests and responses originating outside the Exchange organization   If you select this check box, the Calendar Attendant will process meeting requests that originate outside the Exchange organization. This setting is disabled by default.