Key legal question
Whether the 22 April 1992 guarantee covered the unpaid rent owed by X. AG
Extracted holding
No; the guarantee secured only the debt described in the instrument, namely the rent debt of the named persons or their named partnership, not the later debt of X. AG.
Extracted reasoning
The wording of the guarantee identified the debt concretely by the tenants and by the leased premises' use as a butcher's shop in Bern. The landlords could not in good faith interpret it as covering another company’s debt.