Office 365 Shared Calendar without invitations or reminders?

After a couple of days more research plus 3 calls to O365 support...

1. In Outlook, click on 'Folders', highlight the group which contains the shared calendar.
2. In the Ribbon click 'Home > Membership > Unsubscribe'. User will no longer receive invitations, or reminders for that calendar but will still be able to view/add/edit as permissions allow.

NB. The Organizer of an appointment will always be automatically attending the appointment and therefore it appears in their personal calender, meaning that they still get reminders. Currently it's not possible to prevent this behaviour and the organizer must delete then appointment in their personal calendar in order to prevent reminders popping up.