I have subscribed to the calendars of my colleagues. Each has their individual appointments but some appointments we share. The shared appointments are of course shown next to each other in the calendar view of Outlook. They represent the very same appointment but in different colors from different colleagues.
It would be great if calendar entries like these could be merged into one entry. If needed, the background color of the entry could be mixed (e.g. diagonally striped or some pattern) keeping the information shown who's involved. Or portraits of the involved colleagues could be shown on the entry.
The way it is the entries get unreadable once you've subscribed to more than 3 or 4 calendars.