Русско-англо-русский юридический словарь

accessory obligation. A secondary requirement or duty that must be fulfilled in conjunction with the primary obligation or commitment. When the first obligation is accepted, an accessory obligation can be part of the commitment and expires at the end of the primary obligation. Opposite of principal obligation. (BusinessDictionary)

A principal obligation is one which is the most important object of the engagement of the contracting parties. An accessory obligation is one which is dependent on the principal obligation [...] (lectlaw.com)

When the first obligation is accepted, an accessory obligation can be part of the commitment and expires at the end of the primary obligation. Opposite of principal obligation. (BusinessDictionary)