Percentuale minima di riparto ( Minimum allotment ratio ) : limite inferiore , espresso in termini percentuali , della quota parte di offerte al tasso di interesse marginale da assegnare in un' operazione d' asta . ###>The counterparties » settlement accounts with the national central banks may be used as reserve accounts . Reserve base : the sum of the balance sheet items which constitute the basis for calculating the reserve requirement of a credit institution .