Hi & welcome, Dmitry!  Recently you wrote in a message to All:   
      
    DC>  Where I can find a rules of this echo?   
      
      
                While I have a copy of the official rules, I think the   
   explanation offered by Alexander & Paul will do nicely.  In my experience the   
   sort of folks who ask questions like that never cause any trouble here....  :-)   
      
      
      
      
   --- timEd/386 1.10.y2k+   
    * Origin: Wits' End, Vancouver CANADA (1:153/716)