Kernrechtsfrage
Whether the initial-rent notice was invalid because it omitted the former tenant's rent.
Extrahierter Entscheid
Yes. The omission of the previous rent in the official initial-rent notice was a fatal defect under Art. 270(2) CO, even if the tenants knew the amount by another means.
Extrahierte Begründung
The indication of the prior rent is essential for the tenant's informed choice. A defective notice is invalid as to the rent even without satisfying Art. 270(1) CO conditions.