anchor.diff:      if Exists -> yxrrset;
          true -> check_update_prereqs(PreReqs, RRs) end.
   
  -update_rr(_Key, _Private, [], RRs) -> RRs;
  -update_rr(Key, Private, [{delete, Name}|Updates], RRs) ->
  +update_rr(_Key, [], RRs) -> RRs;
  +update_rr(Key, [{delete, Name}|Updates], RRs) ->
       Now = dns:unix_time(),
       {Match, Diff} = lists:partition(
   		      fun(#dnsxd_couch_rr{name = SN}) ->
   			      dns:dname_to_lower(SN) =:= Name end, RRs),
       NewMatch = [ RR#dnsxd_couch_rr{expire = Now - 1} || RR <- Match ],
       NewRRs = NewMatch ++ Diff,
  -    update_rr(Key, Private, Updates, NewRRs);
  -update_rr(Key, Private, [{delete, Name, Type}|Updates], RRs) ->
  +    update_rr(Key, Updates, NewRRs);
  +update_rr(Key, [{delete, Name, Type}|Updates], RRs) ->
       Now = dns:unix_time(),
       Fun = fun(#dnsxd_couch_rr{name = SN, type = ST}) ->
   		  dns:dname_to_lower(SN) =:= Name andalso ST =:= Type
  
positive.code:     {Match, Diff} = lists:partition(Fun, RRs),
      NewMatch = [ RR#dnsxd_couch_rr{expire = Now - 1} || RR <- Match ],
      NewRRs = NewMatch ++ Diff,
      update_rr(Key, Private, Updates, NewRRs);
  update_rr(Key, Private, [{delete, Name, Type, Data}|Updates], RRs) ->
      Now = dns:unix_time(),
      Fun = fun(#dnsxd_couch_rr{name = SN, type = ST, data = SD}) ->
  		  (dns:dname_to_lower(SN) =:= Name andalso
  
negative.code: 				    type = Type, ttl = TTL, data = Data,
  				    incept = Now, expire = Expire},
  	    NewRRs = [NewRR|RRs],
  	    update_rr(Key, Updates, NewRRs);
  	[#dnsxd_couch_rr{} = RR] ->
  	    NewRR = RR#dnsxd_couch_rr{ttl = TTL, set = Now, expire = Expire},
  	    NewRRs = [NewRR|Diff],
  	    update_rr(Key, Updates, NewRRs);
  	[#dnsxd_couch_rr{} = RR|Dupes] ->
  	    NewRR = RR#dnsxd_couch_rr{ttl = TTL, set = Now, expire = Expire},
  	    NewDupes = [ Dupe#dnsxd_couch_rr{expire = Now - 1}
  			 || Dupe <- Dupes ],
  	    NewRRs = NewDupes ++ [NewRR|Diff],
  	    update_rr(Key, Updates, NewRRs)
      end.
  
  reap(Now, TombstonePeriod, Recs) when is_list(Recs) ->
  