uses
  ActiveX;

procedure TForm1.Button1Click(Sender: TObject);
var
  S: string;
  FormatEtc: TFormatEtc;
  DataObject: IDataObject;
  EnumFormatEtc: IEnumFormatEtc;
begin
  S := '';
  if Succeeded(OleGetClipboard(DataObject)) then
  begin
    if Succeeded(DataObject.EnumFormatEtc(DATADIR_GET, EnumFormatEtc)) then
      while EnumFormatEtc.Next(1, FormatEtc, nil) = S_OK do
        S := S + IntToStr(FormatEtc.cfFormat) + sLineBreak;
    ShowMessage(S);
  end;
end;