One continuing, though localized, puzzle arising from the two month old disruption to the liquidity of global capital markets is the difficulty in drawing any sensible comparisons over the level of retail funding of banks, at least of the Australasian variety.It seems like a straightforward calculation to make: the retail funding ratio is retail deposits divided by total liabilities equals whatever.In practice, working out this ratio for local banks isn't so easy, since banks don't publish information on a consistent basis. And then when banks discuss their levels of retail funding - usually in the course of a bit of boosterism in an investor pitch - the numbers get rather loose.Commonwealth Bank is the latest culprit but by no means the only one. In a discussion of issues around funding and liquidity in a trading update for the September 2007 quarter, published yesterday, CBA said "the recent market volatility has provided the bank with a comparative advantage due to its very high level of retail deposits, which represent 55 percent of the group's total debt funding."The basis of this calculation of a 55 per cent ratio is a bit of a mystery.This newsletter worked out the retail funding ratio for the nine listed banks a few weeks ago (for an article in The Eureka Report), and, according to our calculations, CBA is now overstating its retail funding ratio by nine percentage points. Here's our estimate of the ratios, derived from the average balance sheet data most recently published by each bank.Bendigo, 80.3 per centBank of Queensland, 47.1 per centCommonwealth, 45.8 per centSt George, 42.2 per centSuncorp, 40.4 per centAdelaide, 39.6 per centANZ, 38.0 per centNational, 28.9 per centNote that Westpac's ratio couldn't be worked out from the more limited data available from their financial statements.    CBA yesterday advised that "retail funding includes retail participation in other forms of funding other than deposits. That is the non-wholesale funding." The bank added that, "we do not disclose our methods of calculation."Westpac a few weeks ago in an investor presentation said that its retail funding ratio was 51 per cent, while ANZ has also claimed a ratio of in excess of 50 per cent. In ANZ's case money on deposit through the V2 money market account and Esanda debentures counted as retail funding.The point of all this is not to contend that ANZ, CBA and Westpac are being inherently misleading, but rather that (like a lot of topics of interest in analysing banks) the data leaves a lot to be desired when taking a close look and seeking to draw comparisons.Commonwealth Bank, meanwhile, said in its trading update that it raised more than $2.5 billion in the private term markets "at levels considered attractive given current market conditions". The bank also noted that it "prudently maintained a larger liquidity buffer during this period which will have a slightly negative impact on the net interest margin in the short term." CBA said this may reduce as market conditions improve.CBA said its tier one capital