Key legal question
Whether the cantonal court could require written proof of B.'s authority to represent the company in formation.
Extracted holding
Yes. In case of doubt about the legal existence of a legal person and the representative's powers, the authority may require written proof and set a short deadline, failing which the filing may be treated as withdrawn.
Extracted reasoning
The cantonal procedure rules on collaboration and proof of authority were not applied arbitrarily; the appellants did not show excess formalism or any unbearable result, and the request for documents was justified by contradictory information about the company's registration.