Source : Free On-Line Dictionary of Computing

brain dump
     
        (The act of telling someone) everything one knows about a
        particular topic.  Typically used when someone is going to let
        a new party maintain a piece of code.  Conceptually analogous
        to an operating system {core dump} in that it saves a lot of
        useful {state} before an exit.  "You'll have to give me a
        brain dump on FOOBAR before you start your new job at
        HackerCorp."  At Sun, this is also known as "TOI" (transfer of
        information).
     
        [{Jargon File}]