X properties used in Outlook/Exchange-generated iCalendar


X-MICROSOFT-CDO-ALLDAYEVENT:
	TRUE for an all-day event, FALSE otherwise. CDO does not
	recognize all-day events in the same way Evolution does.
	It requires this property to be set, and expects the DTSTART
	and DTEND to be the boundaries of the day in the local
	time zone, converted to UTC.

X-MICROSOFT-CDO-BUSYSTATUS:
	FREE, TENTATIVE, BUSY, OUTOFOFFICE

X-MICROSOFT-CDO-IMPORTANCE:
	0 (high), 1 (normal), 2 (low)
	corresponding to PRIORITY < 5, == 5, and > 5 respectively

X-MICROSOFT-CDO-INSTTYPE:
	0 - non-recurring
	1 - master entry for a recurring appointment
	2 - single instance of a recurring appointment
	3 - exception to a recurring appointment

X-MICROSOFT-CDO-INTENDEDSTATUS:
	FREE, TENTATIVE, BUSY, OUTOFOFFICE
	used in meeting requests

X-MICROSOFT-CDO-MODPROPS:
	This gets set in iMIP messages with changes to recurring
	meetings, to a list of properties that are different in the
	master instance and the changed instance.

X-MICROSOFT-CDO-OWNERAPPTID:
	Corresponds to http://schemas.microsoft.com/mapi/ownerapptid.
	Uncertain use. Doesn't appear to be mandatory.

X-MICROSOFT-CDO-REPLYTIME:
	The time at which the user took some action with respect to
	this appointment. When accepting a meeting request, should
	be set in both the saved meeting and the reply to the
	organizer. Must also be set in a direct booked meeting.

X-MICROSOFT-CDO-TZID:
	In a VTIMEZONE, gives the CDO id (eg, 10 for EST). Should
	be unset for VTIMEZONEs that aren't from CDO.