anchor.diff:  
   rst_route_tail
   :
  -   srt_discard
  +   srt_active
  +   | srt_discard
      | srt_install
      | srt_next_hop
      | srt_next_table
  +   | srt_passive
      | srt_readvertise
      | srt_reject
      | srt_resolve
  
positive.code:    NEXT_TABLE name = variable
  ;
  
  srt_readvertise
  :
     READVERTISE
  
negative.code:    | rot_static
  ;
  
  srt_active
  :
     ACTIVE
  ;
  
  srt_discard
  :
     DISCARD
  