(22)A reinsurance undertaking conducting reinsurance business in respect of credit insurance, whose credit reinsurance business amounts to more than a small proportion of its total business, should be required to set up an equalisation reserve which does not form part of the solvency margin; that reserve should be calculated according to one of the methods laid down in Directive 73/239/EEC and which are recognised as equivalent; furthermore, this Directive should allow the home Member State also to require reinsurance undertakings whose head office is situated within its territory to set up equalisation reserves for classes of risks other than credit reinsurance, following the rules laid down by that home Member State. Following the introduction of the International Financial Reporting Standards (IFRS 4), this Directive should clarify the prudential treatment of equalisation reserves established in accordance with this Directive. However, since supervision of reinsurance needs to be reassessed under the Solvency II project, this Directive does not pre-empt any future reinsurance supervision under Solvency II.