Brick house.............my Pop's code...........all 10 numbers to be encoded in letters...................only once...............coding.......my maternal grandfather was training me all along...................without me knowing about it......just like Sophie N............in the Da Vinci Code.........................her granddad was the curator of the Louvre.......in Paris.....................Paul.......estab. 1889..........my Pop was the assist. director of Philately.......USPS.............P.S.......................stood for Princess Sophie in the Da Vinci Code.....but in a letter..........it is Post Script........or part of USPS..........Postal Service...........................