Removing all notification observer from a single place

I want to remove a notification observer and I am using the method:

[[NSNotificationCenter defaultCenter] removeObserver: name:@"myNotification" object:nil];

for this. Now there are many observers who are listening to this notification and I want to remove all of them in one shot from a centralised place. Can I pass 'nil' in first parameter and it will remove all observers who are listening to myNotification?