TSMS.UD vs. WideUD

Q: How to determine from what variable to get the text of the received SMS ? UD or WideUD ?

I tried to determine on value of property DCS, but unsuccessfully since DCS is always equal 0.

procedure TForm1.ProcessSMS(aSMS: TSMS);
begin
  if aSMS is TSMSDeliver then
  begin
    with aSMS as TSMSDeliver do
      //here dcs always equal 0
      showmessage(WideUD) or showmessage(UD) ?
  end;
end;

A: If DCS is 0 then use UD. See specification of DCS field, e.g. SMS notes