anchor.diff:  
   %% enum/3
   
  -enum(M, Name, {E,_}) ->
  +enum(M, Name, {_,E}) ->
       B = <<E:32/integer>>,
       B = M:avp(encode, E, Name),
       E = M:avp(decode, B, Name).
   
   retag(import_avps)   -> avp_types;
   retag(import_groups) -> grouped;
  -retag(import_enums)  -> enums;
  +retag(import_enums)  -> enum;
   
   retag(avp_types) -> import_avps;
  -retag(enums)     -> import_enums.
  +retag(enum)     -> import_enums.
   
   %% ===========================================================================
   
  
positive.code: 
  -define(BASE, diameter_gen_base_rfc3588).
  -define(BOOL, [true, false]).
  
  %% ===========================================================================
  %% Interface.
  
negative.code: %% wrapped as for values/1.
  
  values('Enumerated', Name, Mod) ->
      {_Name, Vals} = lists:keyfind(?S(Name), 1, types(enum, Mod)),
      lists:map(fun({_,N}) -> N end, Vals);
  
  values('Grouped', Name, Mod) ->
      Rname = Mod:name2rec(Name),
  