Booking Subject Line

It is really hard to keep up with booking without having to open the invites. There needs to be a way to modify the subject line. For example, I have custom questions that ask the Clients Name. I would like to check a option that allows for a custom question to be included in the booking subject line. Or at least include the customer name in the subject line instead of just the service type. You could have 5 bookings of the the same service and by looking at your calendar you have no idea who they are with, unless you open each booking.