title: XBoard protocol documentation wanted (chess)
body: <p>I am looking for XBoard documentation. XBoard is a communication protocol between chess engines and chess GUIs.</p>
  
  <p>I know about <a href="http://www.gnu.org/software/xboard/engine-intf.html" rel="noreferrer">http://www.gnu.org/software/xboard/engine-intf.html</a> , but seem to miss what a engine has to send/receive for communication with a board. </p>
  
  <p>Anything better then the advice to reverse engineer the protocol either from a GUI Implementation (e.g.: xchess or eboard) or a chess engine would be great. Even a commented snippet from a board/engine communication might help.</p>