2.2.4.7 PidLidAppointmentCounterProposal Property
Type: PtypBoolean ([MS-OXCDATA] section 2.11.1)
When set to TRUE (0x00000001), the PidLidAppointmentCounterProposal property ([MS-OXPROPS] section 2.10) indicates to the organizer that there are counter proposals that have not been accepted or rejected (by the organizer). This property has no meaning for an attendee.