A calendar item is considered conflicting if it occurs, at least in part, at the same time as another calendar item in the same calendar folder. If a calendar item is in a noncalendar folder, it is compared with calendar items in the default calendar folder. Meeting requests are compared with calendar items in the default calendar folder.
The schema that describes this element is located in the EWS virtual directory of the computer that is running Microsoft Exchange Server 2007 that has the Client Access server role installed.