anchor.diff:      %% bucket. Check that none of those are being set to `true'/valid
       %% datatypes.
       ensure_not_present(New, [], [], [{datatype, "`datatype` must not be defined."},
  -                                     {consistent, true, "Fast Path buckets must not be consistent=true"},
  +                                     {consistent, true, "Write once buckets must not be consistent=true"},
                                        {write_once, true, "Cannot set existing bucket type to `write_once`"}]).
   
   %% @private validate that strongly-consistent types and buckets do not
  
positive.code:             ;
          %% if consistent or datatype properties are not defined then properties should be
          %% valid since no other properties generated can be in valid
          {undefined, _AllowMult, _FastPath, Consistent} when Consistent =:= false orelse
                                                   Consistent =:= undefined ->
              true;
          %% if datatype is defined, its not a consistent type and allow_mult=true
          %% then the datatype must be valid
          {Datatype, true, _FastPath,  Consistent} when Consistent =:= false orelse
                                            Consistent =:= undefined ->
              case lists:member(riak_kv_crdt:to_mod(Datatype), ?V2_TOP_LEVEL_TYPES) of
                  true ->
  
negative.code: validate_update_type(consistent, Existing, New) ->
      validate_update_consistent_props(Existing, New);
  validate_update_type(write_once, _Existing, New) ->
      NewWriteOnce = proplists:get_value(write_once, New),
      validate_update_w1c_props(NewWriteOnce, New);
  validate_update_type(datatype, Existing, New) ->
      validate_update_dt_props(Existing, New);
  validate_update_type(default, _Existing, New) ->
  