diff --git a/src/hz.erl b/src/hz.erl
index ffe0168..38ee508 100644
--- a/src/hz.erl
+++ b/src/hz.erl
@@ -1524,16 +1524,34 @@ opaque_type(Params, Pair) when is_map(Pair) ->
     [{Name, TypeArgs}] = maps:to_list(Pair),
     {opaque_type_name(Name), [opaque_type(Params, Arg) || Arg <- TypeArgs]}.
 
-% atoms for builtins, strings (lists) for user-defined types
-opaque_type_name(<<"int">>)      -> integer;
-opaque_type_name(<<"address">>)  -> address;
-opaque_type_name(<<"contract">>) -> contract;
-opaque_type_name(<<"bool">>)     -> boolean;
-opaque_type_name(<<"option">>)   -> option;
-opaque_type_name(<<"list">>)     -> list;
-opaque_type_name(<<"map">>)      -> map;
-opaque_type_name(<<"string">>)   -> string;
-opaque_type_name(Name)           -> binary_to_list(Name).
+% Atoms for builtins, strings (lists) for user-defined types.
+%
+% There are some magic built in types that may or may not also need atoms to
+% represent them, and may or may not need to be handled explicitly in
+% coerce/3, if we can't flatten them directly
+%
+% These types represent some FATE variant:
+% Chain.ttl, AENS.pointee, AENS.name, AENSv2.pointee, AENSv2.name,
+% Chain.ga_meta_tx, Chain.paying_for_tx, Chain.base_tx,
+%
+% And then MCL_BLS12_381.fr represent bytes(32), and MCL_BLS12_381.fp
+% represents bytes(48).
+opaque_type_name(<<"int">>)       -> integer;
+opaque_type_name(<<"bool">>)      -> boolean;
+opaque_type_name(<<"bits">>)      -> bits;
+opaque_type_name(<<"char">>)      -> integer;
+opaque_type_name(<<"string">>)    -> string;
+opaque_type_name(<<"address">>)   -> address;
+opaque_type_name(<<"hash">>)      -> hash;
+opaque_type_name(<<"signature">>) -> signature;
+opaque_type_name(<<"bytes">>)     -> bytes;
+opaque_type_name(<<"contract">>)  -> contract;
+opaque_type_name(<<"list">>)      -> list;
+opaque_type_name(<<"map">>)       -> map;
+opaque_type_name(<<"option">>)    -> option;
+opaque_type_name(<<"name">>)      -> name;
+opaque_type_name(<<"channel">>)   -> channel;
+opaque_type_name(Name)            -> binary_to_list(Name).
 
 % Type preparation has two goals. First, we need a data structure that can be
 % traversed quickly, to take sophia-esque erlang expressions and turn them into