The ItemCount attribute is of type s:int and indicates whether changes to the child elements of this structural element are included into this change report (and therefore SHOULD be processed by the indexing agent). For example, if SPList change notification has ItemCount=7, that means that seven SPListItem change notifications are contained in that SPList change notification.

Note that ultimate change notifications (SPFolder, SPFile, SPView, SPListItem) have no child objects and hence have ItemCount = 0.