Commonwealth Bank put some effort into defending and explaining its capital ratios yesterday; at its annual meeting, the analysts' conference call and in its "pillar 3" disclosures.CBA said its tier one capital ratio was 7.5 per cent using the most conservative methodology. The ratio rises to 8.1 per cent excluding the effect of hedges on interest rate risk, a topic the bank is debating with APRA.As with all major banks, CBA is now keen to emphasise how much higher its capital ratio would be if the rules used in Britain applied in Australia. The ratio would then be 11 per cent for tier one capital and 13.7 per cent for total capital.