I think the point was that Outlook marks appointment time as: Free, Busy, Tentative, or Out of Office.
I am not in a location to test it right now, but for some reason I think the Blackberry keeps track of these but there is no way to see or edit them. I recall that at an old job, I had BES (Blackberry and work PC) but also synced it with my home PC (export only, from Blackberry to home PC) and all the right fields were kept.