OREANDA-NEWS. February 29, 2008. The National Depository Center (NDC) has stopped serving the debtors (NDC is a monopolist in keeping the shareholder registers of Azerbaijan's joint-stock companies). The debtors are required to repay their debts (it is also possible in the form of promissory notes). Twenty emitters had their debt problems solved by issuing promissory notes in 2001-2002, but this has not been practiced since then.