Rule reminder
Italian has gradations of formality: (1) Informal/colloquial, (2) Formal (standard business/professional), (3) Very formal/bureaucratic (administrative, legal, notarial). Very formal Italian uses archaic constructions: 'di cui' (of which), 'ove' (where), 'qualora' (should), 'laddove' (whereas), 'il sottoscritto' (the undersigned), 'Codesta Spettabile Amministrazione' (your distinguished administration). Knowing which level is required is as important as knowing the forms.
In a notarial deed: 'Il bene immobile ___ si tratta è sito in Via Manzoni 5, Milano.' Which relative pronoun is correct?