Regarding /FORCEREBASESUPPRESSALLUPDATES, should this be run against ALL mailboxes (user and resource) or is it recommended only against resource mailboxes?

Q: Regarding /FORCEREBASESUPPRESSALLUPDATES, should this be run against ALL mailboxes (user and resource) or is it recommended only against resource mailboxes? KB 933146 Scenario 3 mentions something about it but I don't understand.
A: This will cause the appointments to be updated, but notifications will not be sent to attendees. Normally you would only use this for resource mailboxes where you are doing direct booking.