Lots of suggestions but none that solve the problem. The Calendar notification tray (not Notification Center) is full of every event anyone adds to a shared calendar waiting for me to click "OK" for some unknown reason. Clicking OK apparently does nothing and serves not purpose other than to fill my Calendar notification tray.
I looked at the support forms linked earlier but it is referencing iCal which tops out at version 4 but on Mountain Lion we are on Calendar version 6. Anyone have a link to a support form for Calendar? I'm having no luck finding it and want to make sure Apple is paying attention to this issue. In the mean-time I will use the icloud feedback form with iCal marked as the software I use with iCloud:
Thanks for contributing TeaMan.
As the comments under this article reiterate, it's the notifications in the IOS Calendar invitations tray that people would also like to turn off.
I've learnt to ignore them in IOS Calendar, BusyCal and iCloud.
(I tend not to launch Mac Calendar)
I'd like to see the option to turn these off added to iCloud as it's the hub distributing the alerts.
They were able to turn off the notifications in Mac OS Mountain Lion, but apparently not in iOS 4, 5, 6 and now 7. Numerous bug reports filed, still not working right. You can even remove the calendars from notification center and the alerts go off. What a bug! I may have to switch away the Apple iPhone until they begin to innovate again and give the consumer what they feel they want. I continue to have and run an Apple Eco-system at my home, however after the Keynote yesterday I went to AT&T right after the show and decided to purchase an HTC One. Hopefully, the magic comes back, but until that time -- I can't have my primary devices buzzing and ringing everytime my brother has a class or wife has an scheduled event.
I had this issue and found the answer that works for all my shared calendars over in the iCal section. There are assumptions made in the workaround though:
1. User is sharing another user's calendar AND doesn't require editing rights (just wants to view the calendar).
2. User doesn't want to see the shared calendar's notifications when they make changes.
3. Apple's use of the term "Public" in the sharing of the calendar doesn't bother you. The Calendar is only available 'publicly' if they have the url. You still have to send an invitation to the shared party and the URL generated for the calendar is not something that could be typically stumbled upon IMHO. The URL for my shared calendars are more than 150 characters long, but it still may an issue to some users.
That said, and Credit to jdubyaelliott who says:
"What I have done as a work-around which seems to work on both OS X and iOS is to have the person change from sharing the calendar with users to making it a public calendar to which others can subscribe. In order to make this change effectively, you first have to have the person sharing their calender REMOVE the individuals who are sharing the calender, THEN close the dialogue box to confirm. After that they can then publish the calendar and invite those they choose. When the subsribers accept the link, they need to be sure to check the "remove alarms" option. The only drawback here is that there is no way that a subscriber can edit the published calendar. Only the owner can do it. That's actually not a bad thing, but just be aware of that."
Here is a link to jdubyaelliott's answer - https://discussions.apple.com/message/22600482#22600482
Hope this helps!