Русско-англо-русский юридический словарь

Articles 1346–49 of the civil code provide rules to govern the subject matter of a transaction. Subject matter of a transaction should be distinguished from the subject matter (or prestation) of an obligation and in turn from the subject matter of the prestation itself, which is the action or abstinence required of the obligor (to do, to give or to refrain). The subject matter of a transaction is, however, often identified by a kind of transposition with that of an obligation. The subject matter is thus the thing or activity on which the transaction is based. In a sale contract, for example, the subject matter is the thing sold and the purchase price; in a letting it is the flat rented and the rent paid for it; in a loan it is the money lent and then repaid; and in a delivery contract is it is the thing sent and the price paid for delivering it.

Subject matter is distinct from the object, which is the aim of the transaction. (Italian Private Law by Guido Alpa, Vincenzo Zeno-Zencovich)