diff --git a/src/util/concepts.hpp b/src/util/concepts.hpp
index a8c7fdd..05c0ffe 100644
--- a/src/util/concepts.hpp
+++ b/src/util/concepts.hpp
@@ -1,12 +1,12 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2014-2017,  Regents of the University of California,
- *                           Arizona Board of Regents,
- *                           Colorado State University,
- *                           University Pierre & Marie Curie, Sorbonne University,
- *                           Washington University in St. Louis,
- *                           Beijing Institute of Technology,
- *                           The University of Memphis.
+ * Copyright (c) 2014-2017 Regents of the University of California,
+ *                         Arizona Board of Regents,
+ *                         Colorado State University,
+ *                         University Pierre & Marie Curie, Sorbonne University,
+ *                         Washington University in St. Louis,
+ *                         Beijing Institute of Technology,
+ *                         The University of Memphis.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
diff --git a/src/util/ethernet.cpp b/src/util/ethernet.cpp
index 40d9391..c880d0c 100644
--- a/src/util/ethernet.cpp
+++ b/src/util/ethernet.cpp
@@ -1,6 +1,12 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2013-2015 Regents of the University of California.
+ * Copyright (c) 2014-2015 Regents of the University of California,
+ *                         Arizona Board of Regents,
+ *                         Colorado State University,
+ *                         University Pierre & Marie Curie, Sorbonne University,
+ *                         Washington University in St. Louis,
+ *                         Beijing Institute of Technology,
+ *                         The University of Memphis.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -136,7 +142,6 @@
 } // namespace util
 } // namespace ndn
 
-
 std::size_t
 std::hash<ndn::util::ethernet::Address>::operator()(const ndn::util::ethernet::Address& a) const noexcept
 {
diff --git a/src/util/ethernet.hpp b/src/util/ethernet.hpp
index ef227d4..30a2b8d 100644
--- a/src/util/ethernet.hpp
+++ b/src/util/ethernet.hpp
@@ -1,12 +1,12 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2014,  Regents of the University of California,
- *                      Arizona Board of Regents,
- *                      Colorado State University,
- *                      University Pierre & Marie Curie, Sorbonne University,
- *                      Washington University in St. Louis,
- *                      Beijing Institute of Technology,
- *                      The University of Memphis
+ * Copyright (c) 2014 Regents of the University of California,
+ *                    Arizona Board of Regents,
+ *                    Colorado State University,
+ *                    University Pierre & Marie Curie, Sorbonne University,
+ *                    Washington University in St. Louis,
+ *                    Beijing Institute of Technology,
+ *                    The University of Memphis.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -112,7 +112,6 @@
 } // namespace util
 } // namespace ndn
 
-
 namespace std {
 
 // specialize std::hash<> for ethernet::Address
diff --git a/src/util/notification-stream.hpp b/src/util/notification-stream.hpp
index e9921c0..d886173 100644
--- a/src/util/notification-stream.hpp
+++ b/src/util/notification-stream.hpp
@@ -1,6 +1,12 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2013-2017 Regents of the University of California.
+ * Copyright (c) 2014-2017 Regents of the University of California,
+ *                         Arizona Board of Regents,
+ *                         Colorado State University,
+ *                         University Pierre & Marie Curie, Sorbonne University,
+ *                         Washington University in St. Louis,
+ *                         Beijing Institute of Technology,
+ *                         The University of Memphis.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -19,32 +25,6 @@
  * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
  */
 
-/**
- * Original copyright notice from NFD:
- *
- * Copyright (c) 2014,  Regents of the University of California,
- *                      Arizona Board of Regents,
- *                      Colorado State University,
- *                      University Pierre & Marie Curie, Sorbonne University,
- *                      Washington University in St. Louis,
- *                      Beijing Institute of Technology,
- *                      The University of Memphis
- *
- * This file is part of NFD (Named Data Networking Forwarding Daemon).
- * See AUTHORS.md for complete list of NFD authors and contributors.
- *
- * NFD 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 Foundation,
- * either version 3 of the License, or (at your option) any later version.
- *
- * NFD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
- * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
- * PURPOSE.  See the GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
- */
-
 #ifndef NDN_UTIL_NOTIFICATION_STREAM_HPP
 #define NDN_UTIL_NOTIFICATION_STREAM_HPP
 
@@ -55,7 +35,6 @@
 #include "concepts.hpp"
 
 namespace ndn {
-
 namespace util {
 
 /** \brief provides a publisher of Notification Stream
@@ -76,9 +55,7 @@
   }
 
   virtual
-  ~NotificationStream()
-  {
-  }
+  ~NotificationStream() = default;
 
   void
   postNotification(const Notification& notification)
diff --git a/src/util/notification-subscriber.cpp b/src/util/notification-subscriber.cpp
index 09a1277..56dee40 100644
--- a/src/util/notification-subscriber.cpp
+++ b/src/util/notification-subscriber.cpp
@@ -1,6 +1,12 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2013-2016 Regents of the University of California.
+ * Copyright (c) 2014-2016 Regents of the University of California,
+ *                         Arizona Board of Regents,
+ *                         Colorado State University,
+ *                         University Pierre & Marie Curie, Sorbonne University,
+ *                         Washington University in St. Louis,
+ *                         Beijing Institute of Technology,
+ *                         The University of Memphis.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -19,32 +25,6 @@
  * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
  */
 
-/**
- * Original copyright notice from NFD:
- *
- * Copyright (c) 2014,  Regents of the University of California,
- *                      Arizona Board of Regents,
- *                      Colorado State University,
- *                      University Pierre & Marie Curie, Sorbonne University,
- *                      Washington University in St. Louis,
- *                      Beijing Institute of Technology,
- *                      The University of Memphis
- *
- * This file is part of NFD (Named Data Networking Forwarding Daemon).
- * See AUTHORS.md for complete list of NFD authors and contributors.
- *
- * NFD 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 Foundation,
- * either version 3 of the License, or (at your option) any later version.
- *
- * NFD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
- * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
- * PURPOSE.  See the GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
- */
-
 #include "notification-subscriber.hpp"
 #include "random.hpp"
 
diff --git a/src/util/notification-subscriber.hpp b/src/util/notification-subscriber.hpp
index 9b86fe1..9387a24 100644
--- a/src/util/notification-subscriber.hpp
+++ b/src/util/notification-subscriber.hpp
@@ -1,6 +1,12 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2013-2016 Regents of the University of California.
+ * Copyright (c) 2014-2016 Regents of the University of California,
+ *                         Arizona Board of Regents,
+ *                         Colorado State University,
+ *                         University Pierre & Marie Curie, Sorbonne University,
+ *                         Washington University in St. Louis,
+ *                         Beijing Institute of Technology,
+ *                         The University of Memphis.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -19,32 +25,6 @@
  * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
  */
 
-/**
- * Original copyright notice from NFD:
- *
- * Copyright (c) 2014,  Regents of the University of California,
- *                      Arizona Board of Regents,
- *                      Colorado State University,
- *                      University Pierre & Marie Curie, Sorbonne University,
- *                      Washington University in St. Louis,
- *                      Beijing Institute of Technology,
- *                      The University of Memphis
- *
- * This file is part of NFD (Named Data Networking Forwarding Daemon).
- * See AUTHORS.md for complete list of NFD authors and contributors.
- *
- * NFD 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 Foundation,
- * either version 3 of the License, or (at your option) any later version.
- *
- * NFD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
- * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
- * PURPOSE.  See the GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
- */
-
 #ifndef NDN_UTIL_NOTIFICATION_SUBSCRIBER_HPP
 #define NDN_UTIL_NOTIFICATION_SUBSCRIBER_HPP