Source : Free On-Line Dictionary of Computing

toto
     
         /toh-toh'/ The default scratch file name among
        French-speaking programmers - in other words, a francophone
        {foo}.  The phonetic mutations "titi", "tata", and "tutu"
        canonically follow "toto", analogously to {bar}, {baz} and
        {quux} in English.
     
        [{Jargon File}]
     
        (1995-04-18)