diff --git a/AUTHORS b/AUTHORS
new file mode 100644
index 0000000..f79c2ed
--- /dev/null
+++ b/AUTHORS
@@ -0,0 +1,2 @@
+Christian Grothoff <christian@grothoff.org>
+Markus Teich <teichm@net.in.tum.de>
diff --git a/brandt.h b/brandt.h
index 39c77ee..4791729 100644
--- a/brandt.h
+++ b/brandt.h
@@ -1,5 +1,5 @@
 /* This file is part of libbrandt.
- * (C) 2016 Markus Teich
+ * Copyright (C) 2016 GNUnet e.V.
  *
  * libbrandt is free software: you can redistribute it and/or modify it under
  * the terms of the GNU General Public License as published by the Free Software
@@ -38,7 +38,7 @@ struct BRANDT_Auction;
  * @param[in] msg The message to be broadcast to all participants of
  * @a auction_closure.
  * @param[in] msg_len The length of the message @a msg in bytes.
- * @return 1 on success, 0 on failure.  FIXME: unusual definition
+ * @return 0 on success, -1 on failure.
  */
 typedef int
 (*BRANDT_BroadcastCallback) (void *auction_closure,
@@ -56,7 +56,7 @@ typedef int
  * auction. This is the Pointer given to BRANDT_join().
  * @param[in] msg The message to be sent to the seller of @a auction_closure.
  * @param[in] msg_len The length of the message @a msg in bytes.
- * @return 1 on success, 0 on failure. FIXME: unusual definition
+ * @return 0 on success, -1 on failure.
  */
 typedef int
 (*BRANDT_UnicastSellerCallback) (void *auction_closure,
@@ -66,23 +66,24 @@ typedef int
 
 /**
  * Functions of this type are called by libbrandt to report the auction outcome
- * to the user.
+ * or malicious/erroneous participants.
  *
- * TODO: update price type. Don't do this notification as a callback?
+ * TODO: update price type.
+ * TODO: export proof of erroneous behaviour.
  *
  * @param[in] auction_closure Closure pointer representing the respective
- * auction. This is the Pointer given to BRANDT_join().
- * @param[in] won 1 if the user has won the auction, 0 otherwise.
+ * auction. This is the Pointer given to BRANDT_join() / BRANDT_new().
+ * @param[in] bidder_id The numeric Id of the bidder this report refers to.
+ * @param[in] status 1 if the user @a bidder_id has won the auction, 0 if he has
+ * lost, -1 if erroneous behaviour was detected.
  * @param[in] price The price, the winner has to pay or 0 if the auction result
  * is private and the user did not win.
  */
 typedef void
 (*BRANDT_ReportResultCallback) (void *auction_closure,
-                                int won,
+                                unsigned int bidder_id,
+                                int status,
                                 uint16_t price);
-// FIXME: the above callback does not work for the seller,
-// but seems to be used for the seller right now.
-// FIXME: also need way to be told about malicious/erroneous participants
 
 
 /**