1. Institutions shall use the internal model to calculate a number which measures losses due to default and internal or external ratings migration at the 99,9 % confidence interval over a time horizon of one year. Institutions shall calculate this number at least weekly.
2. Correlation assumptions shall be supported by analysis of objective data in a conceptually sound framework. The internal model shall appropriately reflect issuer concentrations. Concentrations that can arise within and across product classes under stressed conditions shall also be reflected.
3. The internal IRC model shall reflect the impact of correlations between default and migration events. The impact of diversification between, on the one hand, default and migration events and, on the other hand, other risk factors shall not be reflected.