anchor.diff:  
     if not (Length(aContainerCode) = 11) then
     begin
  -    aErrorMessage:= 'Wrong length. Must be 11 characters.';
  +    aErrorMessage:= SErrorWrongLength;
       exit;
     end;
   
  
positive.code: 
  uses
    mMathUtility;
  
  // http://www.gvct.co.uk/2011/09/how-is-the-check-digit-of-a-container-calculated/
  // https://en.wikipedia.org/wiki/ISO_6346
  
negative.code:   begin
      if (OwnerCode[i] <= 'A') or (OwnerCode[i] >= 'Z') then
      begin
        aErrorMessage:= SErrorWrongOwnerCode;
        exit;
      end;
    end;
  