f all the procedures outlined above are adhered to, the incidence and size of differences should be reduced ; and those mistakes which do occur should be identified and corrected promptly. Failure to observe these principles could leave those responsible bearing the cost, without limit on size or duration, of any differences which arise. All differences must be settled in cash or, by mutual management agreement, by offset against brokerage due. In the absence of agreement otherwise, cash remains the default means of settlement