We use GW8.01 Client and when someone gets a shared calender request and accepts it, it will add the calender to their calender. If that person deletes the shared calender you can never get it back again. If the sharer deletes the new person from allowing to view the calender and adds them again it automatically will say they deleted the calender except if you give more rights which it will send the new person an email saying they have modified rights but you still can't add the calender.

I hope you can follow what I say if you need better clarification I can help. Basically is there a way to manually add a shared calender without getting the email saying to add it to your calender?