Kernrechtsfrage
Whether the lower courts had to examine ex officio the validity of the initial rent for lack of an official form.
Extrahierter Entscheid
No. Under the applicable inquisitorial principle, the court had no duty to investigate a point not raised by the parties and not appearing from the file.
Extrahierte Begründung
Art. 274d para. 3 CO is only a limited inquisitorial rule; it does not remove party responsibility for the factual basis of the case or allow the court to expand the dispute beyond the conclusions and allegations made. Since the absence of the official form did not appear in the record and was not a litigated issue, no ex officio inquiry was required.