Questão jurídica principal
Whether the landlord's termination notice complied with the mandatory form requirement under Art. 266l OR despite only a copy being sent to the tenant.
Decisão extraída
A termination notice for business premises must be served in the prescribed form with the landlord's original signature; a copied form without original signature is not form-valid.
Fundamentação extraída
The termination form requirement is a qualified written form intended to ensure legal certainty and tenant protection. Because the signature is an essential element of this form, sending only an unsigned copy does not satisfy Art. 266l OR; non-compliance makes the termination void under Art. 266o OR.