Host  = <host = [a-z]+ ("." [a-z]+)* > ; 
Path  = <path = [a-z/]* > ; 
Query = <query = [a-z&=]* > ;
URL   = "http://" ${Host} "/" ${Path} "?" ${Query} ; 

// An example: "http://www.google.com/search?q=record&hl=en"