(56)In relation to the validation by competent authorities and ESMA of significant changes to models and parameters adopted to calculate a CCP's margin requirements, default fund contributions, collateral requirements, and other risk-control mechanisms, procedural aspects and the interplay of that validation with the college decision should be clarified. The preliminary adoption of a significant change to the models or parameters should be possible where needed, especially where their swift change is necessary to ensure the soundness of the CCP's risk management.