How to open/use HCL Notes Links in Adobe Reader / Acrobat

What settings are required to be able to open HCL Notes links from PDF documents when Protected View is enabled? How must host entries be formatted?

The following formatted links must be usable: "notes://App01/C1256F540053855C"

If you try to make "notes://" as a host entry, no entry is created in the list.

If I disable Protected View completely, these links can be accessed.