Unfortunately due to a bug in Apple's code, specifying nil as the name does not work.
When nil is specified as name when subscribing as an observer, the notification center should send out all notifications to the handler, when the app is not sandboxed. However, this is not the case.
Apple has been contacted and is aware of the bug, but had no plans of addressing it.
It would be good if Apple either fixed the code or updated the documentation.
"When
nil, the notification center doesn’t use a notification’s name to decide whether to deliver it to the observer."