Banks can reserve financial instruments to be used as collateral should they require additional funding during the day. These instruments have to be in electronic form, that is immobilised at either the Central Depository (CD) or in the Financial Instrument Register (FIR) of the Reserve Bank.
Should a bank not have sufficient funds in its settlement account to carry out a fund-transfer request, the system will automatically determine whether the bank has any financial instruments available to be pledged as collateral for a Reserve Bank loan.