Period of time during which abliquidatir can go back in time...

Period of time during which abliquidatir can go back in time for, review transactions that have occurred and, depending then on how they are characterised, then they might be challenged by the liquidator. If successfully challenged, then the transactions in question can be reversed and quite possibly repaid. Part of the relation back period argument is to ensure that no preference payments have been made along the way. That is, payments in priority to their right of entitlement or positional status (ie: paid ahead of their time, etc).