2.2.6 PidTagFreeBusyEntryIds Property
The PidTagFreeBusyEntryIds property ([MS-OXPROPS] section 2.705) is set on the Root folder and on the Inbox folder of the local message store. The value on the Root folder of the local message store MUST be equal to the value on the Inbox folder. The property contains four binary values, as follows:
The first value is null.
The third value can be the EntryID of the free/busy message of the logged-on user. If the free/busy public folder is unavailable, the third value is null. This value is set when a client initially creates the free/busy message for a user.
The fourth value is the EntryID of the public folder that has its PidTagDisplayName property ([MS-OXCFOLD] section 126.96.36.199.2.5) set to "Freebusy Data". This folder is a child folder of the Root folder of the public folders message store.