(22)It is important that the default of a clearing member does not cause significant losses to other market participants. Therefore, CCPs are required to cover through margins posted by the defaulter, at least, a relevant proportion of the possible loss that during the close out process the CCP might have. Rules should determine the minimum percentage the margins should cover for different classes of financial instruments. Furthermore, CCPs should follow principles to adequately tailor their margin levels to the characteristics of each financial instrument or portfolio they clear.