I wish I could identify very easily, by looking at my day or my week in the calendar, which elements are meetings (with other people invited basically) and which are events or tasks I added myself to perform a specific action or project (therefore without anyother people invited).
This could also work with the invitation I receive when I acknowledge to participate.
There could be a small icon added to the entry when it is a meeting (for instance a group of people next to the time of the event : 👪).