(3)To ensure harmonisation in identification, evaluation, management, and mitigation of interest rate risk in the non-trading book, it is appropriate to lay down standardised assumptions, where possible, in particular with regard to automatic options. When laying down such assumptions, it is necessary to take into account that professional counterparties generally trigger options to their benefit. There may be situations where prescriptive assumptions cannot be made because such assumptions could lead to risk assessments that lack accuracy, as in the case of retail client behaviour to interest rate shocks in the context of specific instruments. For those situations, it is necessary to lay down as much as possible the steps, definitions, and restrictions to estimations that institutions should have regard to.