Posto che OFF lo interpreto come "escluso" in assenza di ulteriore contesto..

Int per me sta per INTEREST
Common Interest--> The percentage of undivided ownership in the common elements belonging to each condominium apartment, as established in the condominium declaration.

e Common elements-->In a condominium , those portions of the property not owned individually by unit owners, but in which an indivisible interest is held by all unit owners. Generally includes the grounds, parking areas, recreational facilities, and external structure of the building.