Interstar, one of the largest providers of low doc home loans and also the fastest growing lenders in Australia, appears to want to persuade investors in mortgage-backed bonds of the differences in styles of low doc loans.The pre-sale reports from credit ratings agencies for Interstar's $2.35 billion equivalent bond which might be the largest mortgage-backed bond sold in one deal by an Australian issuer divide the mortgage funder's low doc loans into distinct slices.Thirty seven per cent of the loan pool is low doc, or "not fully verified," a proportion slightly below some mortgage pools refinanced by Interstar over the last year.Of this, 32 per cent is described as "reduced income verification", in which "Interstar has undertaken a number of steps to reduce the uncertainty."Those steps include fully verifying savings history; credit checks; two-years employment history for self-employed borrowers; mortgage insurance; full valuations; and reviewing borrowers' asset and liability statements declared income for reasonableness.Of the remaining five per cent of "reduced income and savings verification", it's not clear what proportion is subject to valuation.Interstar is selling the mortgage-backed bonds primarily to European investors, with the bonds, denominated in both euros and sterling.