Call blocking in BlackBerry 10 for a known number

We do not need fancy app to block calls. By default, BB10 has option to block all incoming calls or none. Not individually. But there is a better way. Ideally, we should not be blocking calls, because the caller can identify that a call has been blocked or not. It will ring once and then get busy or some other tones. Better way is to just disable all notifications for a number. For that, first save the annoying number to your contacts and in the "Ringtones and Notifications" option for that contact, choose "Phone Calls" and turn off "All Notifications". That is all there is. Now the call gets received, but you would not know unless you look at the phone. No disturbance.