anchor.diff:     PREFERENCE preference = DEC
   ;
   
  -roa_route
  -:
  -  ROUTE
  -  (
  -    prefix = IP_PREFIX
  -    | prefix6 = IPV6_PREFIX
  -  )
  -  roa_common
  -;
  -
   roa_tag
   :
      TAG tag = DEC
  
positive.code: :
     STATION_PORT DEC
  ;
  roa_route
  :
    ROUTE
  
negative.code:     | roa_common
    )
  ;
  
  rof_export
  :
  