If a reserve for contingencies is established, it is well also to install an auxiliary record of it, showing under name of customer or debtor the amount written off, any expenses incurred in connection therewith, and such recoveries as may be realized from time to time. All this may conveniently be shown on a record with the following columns: Date; description in detail; debit; credit; balance. The "balance" column under each account would show the amount contingently due from each customer who may have defaulted. It should not be assumed, however, that the sum total of the balances due from all customers would equal the balance of the reserve in the contingent account. If a control is desired it may be accomplished by setting up, preferably on the first few pages of the auxiliary record, two accounts, one called a contingent asset account, representing the entire amount due from all these debtors, and a liability account, consisting of not only the total due from all customers, but the balance of the contingency reserve as well. By deducting the contingent asset from the contingent liability the balance should equal at all times the balance figure in the reserve for contingencies. Also, the contingent asset account should equal the total amount due from customers on account of depreciated assets. This balance must be maintained, of course, by a control entry process, for example: If a customer's account on the auxiliary record is debited, or increased, the contingent asset account must be increased accordingly, and so on. These control accounts are not considered so vital as the auxiliary record itself showing the amount due from each customer.