diff --git a/src/currency_core/currency_format_utils.h b/src/currency_core/currency_format_utils.h
index 7e28632a..0724d822 100644
--- a/src/currency_core/currency_format_utils.h
+++ b/src/currency_core/currency_format_utils.h
@@ -405,6 +405,25 @@ namespace currency
        return stub;
   }
 
+  template<typename out_t>
+  bool is_out_burned(const out_t& out)          { CHECK_AND_ASSERT_THROW_MES(false, "incorrect out type: " << typeid(out).name()); }
+  bool is_out_burned(const tx_out_bare& o)      { return is_out_burned(o.target); }
+  bool is_out_burned(const txout_to_key& o)     { return o.key == null_pkey; }
+  bool is_out_burned(const tx_out_zarcanum& o)  { return o.stealth_address == null_pkey; }
+  struct zz_is_out_burned_helper_visitor : boost::static_visitor<bool>
+  {
+    template<typename T>
+    bool operator()(const T& v) const { return is_out_burned(v); }
+  };
+  bool is_out_burned(const tx_out_v& v)
+  {
+    return boost::apply_visitor(zz_is_out_burned_helper_visitor(), v);
+  }
+  bool is_out_burned(const txout_target_v& v)
+  {
+    return boost::apply_visitor(zz_is_out_burned_helper_visitor(), v);
+  }
+
   template<class t_extra_container>
   bool add_attachments_info_to_extra(t_extra_container& extra_container, const std::vector<attachment_v>& attachments)
   {
diff --git a/src/currency_core/currency_format_utils_transactions.h b/src/currency_core/currency_format_utils_transactions.h
index 337d40d7..b1424c96 100644
--- a/src/currency_core/currency_format_utils_transactions.h
+++ b/src/currency_core/currency_format_utils_transactions.h
@@ -16,7 +16,7 @@ namespace currency
 {
   struct tx_source_entry
   {
-    typedef serializable_pair<txout_ref_v, crypto::public_key> output_entry; // txout_v is either global output index or ref_by_id; public_key - is output ephemeral pub key
+    typedef serializable_pair<txout_ref_v, crypto::public_key> output_entry; // txout_ref_v is either global output index or ref_by_id; public_key - is output's stealth address
 
     std::vector<output_entry> outputs;  //index + key
     uint64_t real_output;               //index in outputs vector of real output_entry