The privaate mortgages are transactions that are not registered in public sector9and need not to be securitized or mad a public offering burt I read can be made registered as public debt)-i was told that by a procedure (NEED TO KNOW WHAT THE PROCEDURE IS LEGALLY DESCRIBED AS AND THE MECHANICS OF IT-i am sure that this is in some IRS procedures manual or Treasury department manual) done at a bank (i know for sure that it has to be  and has to be a bank with S-2 rating or better and the trust department is able to register the transaction between two private parties as a public "private debt" that is recognized by the US Treasury department as public 'private debt as opposed to public 'public debt (like a mortgage owed to City bank for example or the debt of a city.)