diff --git a/test/x4/actions.cpp b/test/x4/actions.cpp
index e8c609e80..0fd94cb70 100644
--- a/test/x4/actions.cpp
+++ b/test/x4/actions.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/and_predicate.cpp b/test/x4/and_predicate.cpp
index db62bb24e..a61f74afe 100644
--- a/test/x4/and_predicate.cpp
+++ b/test/x4/and_predicate.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/as.cpp b/test/x4/as.cpp
index cec156912..83aca82aa 100644
--- a/test/x4/as.cpp
+++ b/test/x4/as.cpp
@@ -1,5 +1,6 @@
 /*=============================================================================
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/attr.cpp b/test/x4/attr.cpp
index 0a2a0bdf4..750b6a907 100644
--- a/test/x4/attr.cpp
+++ b/test/x4/attr.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/attribute.cpp b/test/x4/attribute.cpp
index 6e2a2b51b..89c6f64cc 100644
--- a/test/x4/attribute.cpp
+++ b/test/x4/attribute.cpp
@@ -1,5 +1,6 @@
 /*=============================================================================
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/attribute_type_check.cpp b/test/x4/attribute_type_check.cpp
index 429812cb4..35f2f053d 100644
--- a/test/x4/attribute_type_check.cpp
+++ b/test/x4/attribute_type_check.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2017-2021 Nikita Kniazev
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/bool.cpp b/test/x4/bool.cpp
index 26833807b..c409117f7 100644
--- a/test/x4/bool.cpp
+++ b/test/x4/bool.cpp
@@ -2,6 +2,7 @@
     Copyright (c) 2001-2011 Hartmut Kaiser
     Copyright (c) 2011 Bryce Lelbach
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/char.cpp b/test/x4/char.cpp
index b9bfc3eef..55f3990eb 100644
--- a/test/x4/char.cpp
+++ b/test/x4/char.cpp
@@ -3,6 +3,7 @@
     Copyright (c) 2001-2011 Hartmut Kaiser
     Copyright (c) 2019 Christian Mazakas
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/char_class.cpp b/test/x4/char_class.cpp
index 88035a8dd..2f0a7aa4a 100644
--- a/test/x4/char_class.cpp
+++ b/test/x4/char_class.cpp
@@ -2,6 +2,7 @@
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2001-2010 Hartmut Kaiser
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/container_support.cpp b/test/x4/container_support.cpp
index 2573a7a8c..794fb498b 100644
--- a/test/x4/container_support.cpp
+++ b/test/x4/container_support.cpp
@@ -2,6 +2,7 @@
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2001-2011 Hartmut Kaiser
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/context.cpp b/test/x4/context.cpp
index edbdf1965..5da8a03d9 100644
--- a/test/x4/context.cpp
+++ b/test/x4/context.cpp
@@ -1,5 +1,6 @@
 /*=============================================================================
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/debug.cpp b/test/x4/debug.cpp
index 2049f94be..3360b303c 100644
--- a/test/x4/debug.cpp
+++ b/test/x4/debug.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/difference.cpp b/test/x4/difference.cpp
index aa88c3adc..4946a2b0a 100644
--- a/test/x4/difference.cpp
+++ b/test/x4/difference.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/eoi.cpp b/test/x4/eoi.cpp
index 1a6621652..2d80e686c 100644
--- a/test/x4/eoi.cpp
+++ b/test/x4/eoi.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/eol.cpp b/test/x4/eol.cpp
index 3ad5a197e..64274d562 100644
--- a/test/x4/eol.cpp
+++ b/test/x4/eol.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/eps.cpp b/test/x4/eps.cpp
index c80919429..4f7f9bd98 100644
--- a/test/x4/eps.cpp
+++ b/test/x4/eps.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/error_handler.cpp b/test/x4/error_handler.cpp
index 80e6f8f4e..b5393bba4 100644
--- a/test/x4/error_handler.cpp
+++ b/test/x4/error_handler.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/expect.cpp b/test/x4/expect.cpp
index 107319339..1ea0b9781 100644
--- a/test/x4/expect.cpp
+++ b/test/x4/expect.cpp
@@ -2,6 +2,7 @@
     Copyright (c) 2001-2013 Joel de Guzman
     Copyright (c) 2017 wanghan02
     Copyright (c) 2024-2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/extract_int.cpp b/test/x4/extract_int.cpp
index 465bfecd0..987a55048 100644
--- a/test/x4/extract_int.cpp
+++ b/test/x4/extract_int.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2018 Nikita Kniazev
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/grammar.cpp b/test/x4/grammar.cpp
index aa8120f50..27772d8cf 100644
--- a/test/x4/grammar.cpp
+++ b/test/x4/grammar.cpp
@@ -2,6 +2,7 @@
     Copyright (c) 2019 Joel de Guzman
     Copyright (c) 2019 Nikita Kniazev
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/grammar.hpp b/test/x4/grammar.hpp
index 5965f2b71..4b93d0590 100644
--- a/test/x4/grammar.hpp
+++ b/test/x4/grammar.hpp
@@ -5,6 +5,7 @@
     Copyright (c) 2019 Joel de Guzman
     Copyright (c) 2019 Nikita Kniazev
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/grammar_linker.cpp b/test/x4/grammar_linker.cpp
index 5c33565dc..13f55ac59 100644
--- a/test/x4/grammar_linker.cpp
+++ b/test/x4/grammar_linker.cpp
@@ -2,6 +2,7 @@
     Copyright (c) 2019 Nikita Kniazev
     Copyright (c) 2019 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/int.cpp b/test/x4/int.cpp
index 1d9e0eb7c..5b37b9e47 100644
--- a/test/x4/int.cpp
+++ b/test/x4/int.cpp
@@ -3,6 +3,7 @@
     Copyright (c) 2001-2011 Hartmut Kaiser
     Copyright (c) 2011 Bryce Lelbach
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/iterator.cpp b/test/x4/iterator.cpp
index 10b611712..cdca8e1d5 100644
--- a/test/x4/iterator.cpp
+++ b/test/x4/iterator.cpp
@@ -2,6 +2,7 @@
     Copyright (c) 2001-2017 Joel de Guzman
     Copyright (c) 2017 think-cell GmbH
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/kleene.cpp b/test/x4/kleene.cpp
index 9592e4cb7..4d325c616 100644
--- a/test/x4/kleene.cpp
+++ b/test/x4/kleene.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/lexeme.cpp b/test/x4/lexeme.cpp
index dc9154393..e6a7b7159 100644
--- a/test/x4/lexeme.cpp
+++ b/test/x4/lexeme.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/list.cpp b/test/x4/list.cpp
index 4c7e858a9..64e9a7031 100644
--- a/test/x4/list.cpp
+++ b/test/x4/list.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2013 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/lit.cpp b/test/x4/lit.cpp
index 001717caf..ada8ff01a 100644
--- a/test/x4/lit.cpp
+++ b/test/x4/lit.cpp
@@ -2,6 +2,7 @@
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2001-2011 Hartmut Kaiser
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/matches.cpp b/test/x4/matches.cpp
index 0f1037070..053374acc 100644
--- a/test/x4/matches.cpp
+++ b/test/x4/matches.cpp
@@ -2,6 +2,7 @@
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2001-2010 Hartmut Kaiser
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/no_case.cpp b/test/x4/no_case.cpp
index d4af912a6..23ba90191 100644
--- a/test/x4/no_case.cpp
+++ b/test/x4/no_case.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/no_skip.cpp b/test/x4/no_skip.cpp
index de9a1ce41..4e6197490 100644
--- a/test/x4/no_skip.cpp
+++ b/test/x4/no_skip.cpp
@@ -2,6 +2,7 @@
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2013 Agustin Berge
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/not_predicate.cpp b/test/x4/not_predicate.cpp
index 8832ce46d..32315d748 100644
--- a/test/x4/not_predicate.cpp
+++ b/test/x4/not_predicate.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/omit.cpp b/test/x4/omit.cpp
index efda3f60f..75e754e99 100644
--- a/test/x4/omit.cpp
+++ b/test/x4/omit.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/optional.cpp b/test/x4/optional.cpp
index f0d8e60c6..41d60c9f7 100644
--- a/test/x4/optional.cpp
+++ b/test/x4/optional.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/parser.cpp b/test/x4/parser.cpp
index 5b24c522e..830b70a6e 100644
--- a/test/x4/parser.cpp
+++ b/test/x4/parser.cpp
@@ -1,5 +1,6 @@
 /*=============================================================================
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/plus.cpp b/test/x4/plus.cpp
index 39e343675..502b6d921 100644
--- a/test/x4/plus.cpp
+++ b/test/x4/plus.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/real.hpp b/test/x4/real.hpp
index 9099bd21b..6aecbcd6a 100644
--- a/test/x4/real.hpp
+++ b/test/x4/real.hpp
@@ -5,6 +5,7 @@
     Copyright (c) 2001-2010 Joel de Guzman
     Copyright (c) 2001-2010 Hartmut Kaiser
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/real1.cpp b/test/x4/real1.cpp
index a54d78e26..824c3b45a 100644
--- a/test/x4/real1.cpp
+++ b/test/x4/real1.cpp
@@ -3,6 +3,7 @@
     Copyright (c) 2001-2011 Hartmut Kaiser
     Copyright (c) 2011 Bryce Lelbach
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/real2.cpp b/test/x4/real2.cpp
index f4165dfdc..c473c60dd 100644
--- a/test/x4/real2.cpp
+++ b/test/x4/real2.cpp
@@ -3,6 +3,7 @@
     Copyright (c) 2001-2011 Hartmut Kaiser
     Copyright (c) 2011 Bryce Lelbach
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/real3.cpp b/test/x4/real3.cpp
index 5be7abfa0..0ca8903d8 100644
--- a/test/x4/real3.cpp
+++ b/test/x4/real3.cpp
@@ -2,6 +2,7 @@
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2001-2010 Hartmut Kaiser
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/repeat.cpp b/test/x4/repeat.cpp
index f24d4c362..e035ba537 100644
--- a/test/x4/repeat.cpp
+++ b/test/x4/repeat.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2011 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/rule1.cpp b/test/x4/rule1.cpp
index b99cc00d8..bb942b585 100644
--- a/test/x4/rule1.cpp
+++ b/test/x4/rule1.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/rule2.cpp b/test/x4/rule2.cpp
index d4dbf2627..a368c4b94 100644
--- a/test/x4/rule2.cpp
+++ b/test/x4/rule2.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/rule_separate_tu.cpp b/test/x4/rule_separate_tu.cpp
index cf337813e..8f849d768 100644
--- a/test/x4/rule_separate_tu.cpp
+++ b/test/x4/rule_separate_tu.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2019 Nikita Kniazev
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/rule_separate_tu_grammar.cpp b/test/x4/rule_separate_tu_grammar.cpp
index 7c118704f..21504ed84 100644
--- a/test/x4/rule_separate_tu_grammar.cpp
+++ b/test/x4/rule_separate_tu_grammar.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2019 Nikita Kniazev
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/rule_separate_tu_grammar.hpp b/test/x4/rule_separate_tu_grammar.hpp
index 1bae89922..5c0a8b257 100644
--- a/test/x4/rule_separate_tu_grammar.hpp
+++ b/test/x4/rule_separate_tu_grammar.hpp
@@ -4,6 +4,7 @@
 /*=============================================================================
     Copyright (c) 2019 Nikita Kniazev
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/seek.cpp b/test/x4/seek.cpp
index 9cc1807bb..26eb082f9 100644
--- a/test/x4/seek.cpp
+++ b/test/x4/seek.cpp
@@ -2,6 +2,7 @@
     Copyright (c) 2011 Jamboree
     Copyright (c) 2014 Lee Clagett
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/skip.cpp b/test/x4/skip.cpp
index d0b232f3e..f371fb0bd 100644
--- a/test/x4/skip.cpp
+++ b/test/x4/skip.cpp
@@ -2,6 +2,7 @@
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2013 Agustin Berge
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/symbols1.cpp b/test/x4/symbols1.cpp
index 1df8e4b0d..048c30a60 100644
--- a/test/x4/symbols1.cpp
+++ b/test/x4/symbols1.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/symbols2.cpp b/test/x4/symbols2.cpp
index d503395d5..c963dea07 100644
--- a/test/x4/symbols2.cpp
+++ b/test/x4/symbols2.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/symbols3.cpp b/test/x4/symbols3.cpp
index 67c9ed5e5..3f6ce634a 100644
--- a/test/x4/symbols3.cpp
+++ b/test/x4/symbols3.cpp
@@ -2,6 +2,7 @@
     Copyright (c) 2013 Carl Barron
     Copyright (c) 2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/test.hpp b/test/x4/test.hpp
index 3caa3818b..cc7a1d75d 100644
--- a/test/x4/test.hpp
+++ b/test/x4/test.hpp
@@ -5,6 +5,7 @@
     Copyright (c) 2001-2013 Joel de Guzman
     Copyright (c) 2019 Nikita Kniazev
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/to_utf8.cpp b/test/x4/to_utf8.cpp
index 1191cc159..babbff4c9 100644
--- a/test/x4/to_utf8.cpp
+++ b/test/x4/to_utf8.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2018-2023 Nikita Kniazev
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/tst.cpp b/test/x4/tst.cpp
index 78224e702..e119c97af 100644
--- a/test/x4/tst.cpp
+++ b/test/x4/tst.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2001-2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/uint.cpp b/test/x4/uint.cpp
index 33530e332..c1dc189bc 100644
--- a/test/x4/uint.cpp
+++ b/test/x4/uint.cpp
@@ -3,6 +3,7 @@
     Copyright (c) 2001-2011 Hartmut Kaiser
     Copyright (c) 2011 Bryce Lelbach
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/uint_radix.cpp b/test/x4/uint_radix.cpp
index c73c101b3..fedb891cf 100644
--- a/test/x4/uint_radix.cpp
+++ b/test/x4/uint_radix.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2011 Jan Frederick Eick
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/unused.cpp b/test/x4/unused.cpp
index 46d45cced..2ee5ef4bb 100644
--- a/test/x4/unused.cpp
+++ b/test/x4/unused.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2019 Nikita Kniazev
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/with.cpp b/test/x4/with.cpp
index 8ac6236dd..6ec17927e 100644
--- a/test/x4/with.cpp
+++ b/test/x4/with.cpp
@@ -1,6 +1,7 @@
 /*=============================================================================
     Copyright (c) 2015 Joel de Guzman
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/with_local.cpp b/test/x4/with_local.cpp
index 219d6eaa5..c5e5ae2c7 100644
--- a/test/x4/with_local.cpp
+++ b/test/x4/with_local.cpp
@@ -1,5 +1,6 @@
 /*=============================================================================
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
diff --git a/test/x4/x3_rule_problem.cpp b/test/x4/x3_rule_problem.cpp
index d8c51b5a5..9ed42abfd 100644
--- a/test/x4/x3_rule_problem.cpp
+++ b/test/x4/x3_rule_problem.cpp
@@ -1,5 +1,6 @@
 /*=============================================================================
     Copyright (c) 2025 Nana Sakisaka
+    Copyright (c) 2026 The Iris Project Contributors
 
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)