title: Handling a Keypress in C# with e.handled
body: <p>I found this C# keystroke handler code using Reflector,</p>
  
  <p><strong>e.Handled = "23467CDEFGHJKLMNPQRTUVWXYZ-\x0003\x0016\x0018\b".IndexOf(ch) == -1;</strong></p>
  
  <p>I understand most of it except the <strong>"\x0003\x0016\x0018\b"</strong> part of it. Can anyone tell me what that does. Thanks</p>