When the Agency’s debts, other than the State subsidy referred to in 1° of article R. 232-27, cannot be recovered out of court, proceedings shall be conducted in accordance with commercial practice or may be the subject of statements of enforceability issued by the Chairman of the Agency. Enforceable statements may be notified to debtors by registered letter with acknowledgement of receipt. Recovery is pursued until opposition is lodged with the competent court.