diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 19b94e29..f62a1b90 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -6,4 +6,49 @@ Drive your browser there for a lot of useful information on GrafX2 development,
 internals, and roadmap.
 
 You can also join the #grafx2 channel on Freenode for more direct interaction
-with other developers.
\ No newline at end of file
+with other developers.
+
+GrafX2 is distributed under the GPL license, version 2 (with some files under
+less restrictive or compatible licenses, as indicated in the file headers).
+Please make sure the code you contribute to GrafX2 is suitable for distribution
+under such a license as mentionned in this certificate of origin:
+
+-------------------------------------------------------------------------------
+
+Developer Certificate of Origin
+Version 1.1
+
+Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
+1 Letterman Drive
+Suite D4700
+San Francisco, CA, 94129
+
+Everyone is permitted to copy and distribute verbatim copies of this
+license document, but changing it is not allowed.
+
+
+Developer's Certificate of Origin 1.1
+
+By making a contribution to this project, I certify that:
+
+(a) The contribution was created in whole or in part by me and I
+    have the right to submit it under the open source license
+    indicated in the file; or
+
+(b) The contribution is based upon previous work that, to the best
+    of my knowledge, is covered under an appropriate open source
+    license and I have the right under that license to submit that
+    work with modifications, whether created in whole or in part
+    by me, under the same open source license (unless I am
+    permitted to submit under a different license), as indicated
+    in the file; or
+
+(c) The contribution was provided directly to me by some other
+    person who certified (a), (b) or (c) and I have not modified
+    it.
+
+(d) I understand and agree that this project and the contribution
+    are public and that a record of the contribution (including all
+    personal information I submit with it, including my sign-off) is
+    maintained indefinitely and may be redistributed consistent with
+    this project or the open source license(s) involved.
diff --git a/COPYRIGHT.txt b/COPYRIGHT.txt
new file mode 100644
index 00000000..161513d0
--- /dev/null
+++ b/COPYRIGHT.txt
@@ -0,0 +1,124 @@
+GrafX2 is distributed under GPLv2; however, some files are imported from other
+projects and have different licenses. Here is a list of the GrafX2 contributors,
+as well as a list of files with different ownership or license.
+
+6502.{c,h}
+===========
+
+Copyright 1999-2018 Manuel Sainz de Baranda y Goñi.
+
+GNU GPL version 3.
+
+6502types.h
+===========
+
+unknown
+
+cpc_scr_simple_loader.h
+=======================
+
+unknown
+
+impdraw_loader.h
+================
+
+Copyright 2018 AsT/iMP4CT
+
+Incuded in GrafX2 with the author's authorization granted here:
+https://amstradplus.forumforever.com/t462-iMPdraw-v2-0.htm?start=45
+
+This code is embedded by GrafX2 in saved images for some file formats. You are
+free to use the generated images without any restrictions or obligations
+caused by the use of this code.
+
+misc/c64viewer/*
+================
+
+Copyright 2019 Thomas Bernard
+
+This code is embedded by GrafX2 in saved images for some file formats. You are
+free to use the generated images without any restrictions or obligations
+caused by the use of this code.
+
+libraw2crtc.{c,h}
+=================
+
+Copyright 2008 CloudStrife
+
+Originally under licence libre CeCILL v2. This license allows reuse in GrafX2
+and diffusion under the GPL version 2 (section 5.3.4 of the license).
+
+mountlist.{c,h}
+===============
+
+Copyright (C) 1991, 1992, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
+2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+
+GNU GPL version 2 or later.
+
+realpath.c
+==========
+
+Portions from GeekGadgets for Amiga. Copyright and license unknown.
+
+recoil.{c,h}
+============
+
+These files are generated from recoil sources at build time.
+
+Copyright 2014-2020 Piotr Fusik	and other recoil authors.
+
+GNU GPL version 2 or later.
+
+SDLMain.{m,h}
+=========
+
+Copyright ???? Darrell Walisser
+Copyright ???? Max Horn
+
+These files were released with the SDL library under the GNU LGPL v2.1.
+
+SFont.{c,h}
+===========
+
+SFont 2.03 from http://www.linux-games.com/sfont/
+
+Copyright 2018 Thomas Bernard
+Copyright 2011 Yves Rizoud
+Copyright 2003 Karl Bartel
+Copyright 2002 Florian Hufsky
+Copyright 2000 Matthias Braun
+
+GNU GPL version 2 or later, or GNU LGPL 2.1 or later.
+
+Other files
+===========
+
+Copyright 2020 Lai Kwun Hang
+Copyright 2019 Jaume Delclòs Coll
+Copyright 2019 Romain Graillot
+Copyright 2019 Helmut Grohne
+Copyright 2018-2020 Ryo Onodera
+Copyright 2018-2019 Nic Soudée
+Copyright 2018-2019 François Revol
+Copyright 2018 Frederic Cambus
+Copyright 2018 Jordan Christiansen
+Copyright 2018 Alex Myczko
+Copyright 2018 Alexander Wilms
+Copyright 2018 Philip Linde
+Copyright 2017-2020 Thomas Bernard
+Copyright 2015-2018 Adrian Castravete
+Copyright 2014 Sergii Pylypenko
+Copyright 2012 Matthias Ruster (mazzearos)
+Copyright 2011-2012 Pawel Góralski (nokturnal)
+Copyright 2010 Alexander Filyanov
+Copyright 2009 Pasi Kallinen
+Copyright 2009 Petter Lindquist
+Copyright 2010 Fernando Mastandrea (masta.uy)
+Copyright 2008-2009 Peter Gordon
+Copyright 2008-2012 Franck Charlet
+Copyright 2008-2020 Yves Rizoud
+Copyright 2007-2020 Adrien Destugues
+Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+
+GNU GPL version 2.
diff --git a/misc/c64viewer/picview.asm b/misc/c64viewer/picview.asm
index e5d74bb8..fba71494 100644
--- a/misc/c64viewer/picview.asm
+++ b/misc/c64viewer/picview.asm
@@ -1,4 +1,10 @@
 ; vim:ts=8 sw=8:
+;  Grafx2 - The Ultimate 256-color bitmap paint program
+;
+;	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
+;
+; This code is embedded in C64 images saved by GrafX2, it can be distributed
+; and modified without any restrictions.
 .word $0801
 .org  $0801
 	.word next, 1911	; next basic line and line number
diff --git a/src/SFont.c b/src/SFont.c
index e2304b3b..ebb56b23 100644
--- a/src/SFont.c
+++ b/src/SFont.c
@@ -4,6 +4,7 @@
     Copyright (C) 2003 Karl Bartel
 
     GrafX2 Modification
+    Copyright (c) 2011 Yves Rizoud
     Copyright (c) 2018 Thomas Bernard
 
     License: GPL or LGPL (at your choice)
@@ -29,6 +30,13 @@
     karlb@gmx.net
 */
 
+/* This file is based on SFont 2.03 was modified for GrafX2:
+  - SDL2 support
+  - Automatic space width detection
+  - Handling of missing lowercase characters
+  - Multiline support
+*/
+
 #include <assert.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/src/bitcount.h b/src/bitcount.h
index e2253cd7..6e95511c 100644
--- a/src/bitcount.h
+++ b/src/bitcount.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/brush.c b/src/brush.c
index 20a32125..a9a819d1 100644
--- a/src/brush.c
+++ b/src/brush.c
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008      Franck Charlet
-    Copyright 2007-2008 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/brush.h b/src/brush.h
index 45d2b32f..6b38f6c9 100644
--- a/src/brush.h
+++ b/src/brush.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007-2008 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/brush_ops.c b/src/brush_ops.c
index 91a4a799..1d88b54e 100644
--- a/src/brush_ops.c
+++ b/src/brush_ops.c
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 2009 Franck Charlet
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/buttons.c b/src/buttons.c
index 2cff705d..5b0a6add 100644
--- a/src/buttons.c
+++ b/src/buttons.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Yves Rizoud
-    Copyright 2007-2017 Adrien Destugues (PulkoMandy)
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/buttons.h b/src/buttons.h
index 88c270b8..29d352c8 100644
--- a/src/buttons.h
+++ b/src/buttons.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/buttons_effects.c b/src/buttons_effects.c
index 4fdb6e5a..7f2d74ca 100644
--- a/src/buttons_effects.c
+++ b/src/buttons_effects.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2008 Yves Rizoud
-    Copyright 2007-2017 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/c64formats.c b/src/c64formats.c
index 00a3098e..b8be1edc 100644
--- a/src/c64formats.c
+++ b/src/c64formats.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018-2019 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Petter Lindquist
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007-2011 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/c64load.c b/src/c64load.c
index 9cc97e8f..db073837 100644
--- a/src/c64load.c
+++ b/src/c64load.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018-2019 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Petter Lindquist
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007-2011 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/c64load.h b/src/c64load.h
index 58f96c3b..7282a095 100644
--- a/src/c64load.h
+++ b/src/c64load.h
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018-2019 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Petter Lindquist
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007-2011 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/c64picview_inc.h b/src/c64picview_inc.h
index dc7df1e9..3ce89e5d 100644
--- a/src/c64picview_inc.h
+++ b/src/c64picview_inc.h
@@ -1,3 +1,23 @@
+/* vim:expandtab:ts=2 sw=2:
+*/
+/*  Grafx2 - The Ultimate 256-color bitmap paint program
+
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
+
+    Grafx2 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; version 2
+    of the License.
+
+    Grafx2 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 Grafx2; if not, see <http://www.gnu.org/licenses/>
+*/
+/* Sourcecode for this C64 binary is available in misc/c64viewer */
 static unsigned char picview_prg[] = {
   0x01, 0x08, 0x0b, 0x08, 0x77, 0x07, 0x9e, 0x32, 0x30, 0x36, 0x31, 0x00,
   0x00, 0x00, 0xa9, 0x48, 0x85, 0xfb, 0xa9, 0x09, 0x85, 0xfc, 0xa2, 0x10,
diff --git a/src/colorred.c b/src/colorred.c
index bcab5848..8685dd3f 100644
--- a/src/colorred.c
+++ b/src/colorred.c
@@ -2,7 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2011 Adrien Destugues
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/colorred.h b/src/colorred.h
index 10761484..b9dbb4d4 100644
--- a/src/colorred.h
+++ b/src/colorred.h
@@ -2,7 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2011 Adrien Destugues
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/const.h b/src/const.h
index 73fbddcf..1875a6bb 100644
--- a/src/const.h
+++ b/src/const.h
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2014 Sergii Pylypenko
-    Copyright 2008 Yves Rizoud
-    Copyright 2007-2017 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/cpcformats.c b/src/cpcformats.c
index a6599a35..bf312ba5 100644
--- a/src/cpcformats.c
+++ b/src/cpcformats.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018-2019 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Petter Lindquist
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007-2019 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/engine.c b/src/engine.c
index b92af4ea..fab01eea 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/engine.h b/src/engine.h
index 155aa5f0..fe5f1215 100644
--- a/src/engine.h
+++ b/src/engine.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/errors.h b/src/errors.h
index 44ebc1dc..99d2c1ad 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -2,7 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Adrien Destugues
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/factory.c b/src/factory.c
index c82f9015..f20071a9 100644
--- a/src/factory.c
+++ b/src/factory.c
@@ -2,7 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2009-2011 Adrien Destugues
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/factory.h b/src/factory.h
index 8c5b835c..afc47947 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -1,5 +1,22 @@
 /* vim:expandtab:ts=2 sw=2:
 */
+/*  Grafx2 - The Ultimate 256-color bitmap paint program
+
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
+
+    Grafx2 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; version 2
+    of the License.
+
+    Grafx2 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 Grafx2; if not, see <http://www.gnu.org/licenses/>
+*/
 #ifndef FACTORY_H__
 #define FACTORY_H__
 
diff --git a/src/fileformats.c b/src/fileformats.c
index f6d47b46..22aa32ea 100644
--- a/src/fileformats.c
+++ b/src/fileformats.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Petter Lindquist
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/fileformats.h b/src/fileformats.h
index 7eee999f..adbc3b2d 100644
--- a/src/fileformats.h
+++ b/src/fileformats.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018-2019 Thomas Bernard
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/filesel.c b/src/filesel.c
index 99db5494..73b818dd 100644
--- a/src/filesel.c
+++ b/src/filesel.c
@@ -2,14 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2014 Sergii Pylypenko
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Franck Charlet
-    Copyright 2008 Peter Gordon
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/filesel.h b/src/filesel.h
index b2eb912f..49194d7e 100644
--- a/src/filesel.h
+++ b/src/filesel.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/fileseltools.c b/src/fileseltools.c
index b8f6b37a..fcd46b9e 100644
--- a/src/fileseltools.c
+++ b/src/fileseltools.c
@@ -2,14 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018-2020 Thomas Bernard
-    Copyright 2014 Sergii Pylypenko
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Franck Charlet
-    Copyright 2008 Peter Gordon
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/fileseltools.h b/src/fileseltools.h
index aea5e8a3..51928376 100644
--- a/src/fileseltools.h
+++ b/src/fileseltools.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018-2020 Thomas Bernard
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/generatedoc.c b/src/generatedoc.c
index baaffc83..e87d7ad0 100644
--- a/src/generatedoc.c
+++ b/src/generatedoc.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Pasi Kallinen
-    Copyright 2008 Peter Gordon
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/gfx2log.c b/src/gfx2log.c
index b855af68..40ca476e 100644
--- a/src/gfx2log.c
+++ b/src/gfx2log.c
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/gfx2log.h b/src/gfx2log.h
index 89a25529..17542451 100644
--- a/src/gfx2log.h
+++ b/src/gfx2log.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/gfx2mem.c b/src/gfx2mem.c
index a8d3bad1..765296d7 100644
--- a/src/gfx2mem.c
+++ b/src/gfx2mem.c
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2019 Thomas Bernard
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/gfx2mem.h b/src/gfx2mem.h
index 6ff1bca9..311e885b 100644
--- a/src/gfx2mem.h
+++ b/src/gfx2mem.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2019 Thomas Bernard
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/gfx2surface.c b/src/gfx2surface.c
index 1e5c0e1a..d46e62fc 100644
--- a/src/gfx2surface.c
+++ b/src/gfx2surface.c
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/gfx2surface.h b/src/gfx2surface.h
index 0af271ff..1d7c8026 100644
--- a/src/gfx2surface.h
+++ b/src/gfx2surface.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/giformat.c b/src/giformat.c
index 487a075d..bf2b7d01 100644
--- a/src/giformat.c
+++ b/src/giformat.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Petter Lindquist
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/global.h b/src/global.h
index 23c93230..ef44412f 100644
--- a/src/global.h
+++ b/src/global.h
@@ -2,11 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2014 Sergii Pylypenko
-    Copyright 2009 Franck Charlet
-    Copyright 2009 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/graph.c b/src/graph.c
index 2a183a37..d5c005fa 100644
--- a/src/graph.c
+++ b/src/graph.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2008 Franck Charlet
-    Copyright 2007-2017 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/graph.h b/src/graph.h
index a6c290bf..cfe29100 100644
--- a/src/graph.h
+++ b/src/graph.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2007-2008 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/haiku.h b/src/haiku.h
index c23fb940..07349b55 100644
--- a/src/haiku.h
+++ b/src/haiku.h
@@ -1,3 +1,20 @@
+/*  Grafx2 - The Ultimate 256-color bitmap paint program
+
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
+
+    Grafx2 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; version 2
+    of the License.
+
+    Grafx2 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 Grafx2; if not, see <http://www.gnu.org/licenses/>
+*/
 /** @file haiku.h
  * Declarations of HAIKU specific functions.
  *
diff --git a/src/help.c b/src/help.c
index ae8a0e84..b2875467 100644
--- a/src/help.c
+++ b/src/help.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Peter Gordon
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/help.h b/src/help.h
index 6fa1b730..8bd4c916 100644
--- a/src/help.h
+++ b/src/help.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/helpfile.h b/src/helpfile.h
index f7e7b434..69d5f8ba 100644
--- a/src/helpfile.h
+++ b/src/helpfile.h
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2008 Yves Rizoud
-    Copyright 2009 Franck Charlet
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/hotkeys.c b/src/hotkeys.c
index 6d2ee251..e30e39d5 100644
--- a/src/hotkeys.c
+++ b/src/hotkeys.c
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/hotkeys.h b/src/hotkeys.h
index 273a512d..d82693e7 100644
--- a/src/hotkeys.h
+++ b/src/hotkeys.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/ifformat.c b/src/ifformat.c
index 1573abb9..892c8e87 100644
--- a/src/ifformat.c
+++ b/src/ifformat.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Petter Lindquist
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/init.c b/src/init.c
index 3e384eb4..02ac3969 100644
--- a/src/init.c
+++ b/src/init.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2019 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Peter Gordon
-    Copyright 2008 Yves Rizoud
-    Copyright 2009 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/init.h b/src/init.h
index b654fa15..96adb99a 100644
--- a/src/init.h
+++ b/src/init.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/init_buttons.h b/src/init_buttons.h
index 087d0a91..7947f623 100644
--- a/src/init_buttons.h
+++ b/src/init_buttons.h
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2019 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Peter Gordon
-    Copyright 2008 Yves Rizoud
-    Copyright 2009 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/input.c b/src/input.c
index 50e155e6..b8d5bd55 100644
--- a/src/input.c
+++ b/src/input.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2009 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/input.h b/src/input.h
index 45b09993..da9886b0 100644
--- a/src/input.h
+++ b/src/input.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/io.c b/src/io.c
index 9cc690c3..ab649046 100644
--- a/src/io.c
+++ b/src/io.c
@@ -2,11 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/io.h b/src/io.h
index 9362ec57..12364b2b 100644
--- a/src/io.h
+++ b/src/io.h
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Yves Rizoud
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/keyboard.c b/src/keyboard.c
index eb7df899..dde07f59 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2010 Alexander Filyanov
-    Copyright 2009 Franck Charlet
-    Copyright 2008 Yves Rizoud
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/keyboard.h b/src/keyboard.h
index 7a798301..2b24b9eb 100644
--- a/src/keyboard.h
+++ b/src/keyboard.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/keycodes.h b/src/keycodes.h
index 8e8d05a4..71a4d397 100644
--- a/src/keycodes.h
+++ b/src/keycodes.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/layers.c b/src/layers.c
index c5e37af0..a291840f 100644
--- a/src/layers.c
+++ b/src/layers.c
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2009 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/layers.h b/src/layers.h
index 3fe79016..74be45f5 100644
--- a/src/layers.h
+++ b/src/layers.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2009 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/loadrecoil.c b/src/loadrecoil.c
index f6cdc9a3..112b12af 100644
--- a/src/loadrecoil.c
+++ b/src/loadrecoil.c
@@ -2,7 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/loadsave.c b/src/loadsave.c
index 94a84c89..5fddd166 100644
--- a/src/loadsave.c
+++ b/src/loadsave.c
@@ -2,14 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2010 Alexander Filyanov
-    Copyright 2009 Petter Lindquist
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/loadsave.h b/src/loadsave.h
index d9a9aed0..08315145 100644
--- a/src/loadsave.h
+++ b/src/loadsave.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/loadsavefuncs.c b/src/loadsavefuncs.c
index 6dffba7c..82dafb7d 100644
--- a/src/loadsavefuncs.c
+++ b/src/loadsavefuncs.c
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2019 Thomas Bernard
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/loadsavefuncs.h b/src/loadsavefuncs.h
index 1cdaca33..e9ec4e50 100644
--- a/src/loadsavefuncs.h
+++ b/src/loadsavefuncs.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2019 Thomas Bernard
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/main.c b/src/main.c
index 7c7d3141..d3612b22 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Pasi Kallinen
-    Copyright 2008 Peter Gordon
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/misc.c b/src/misc.c
index f5498c1e..ead79562 100644
--- a/src/misc.c
+++ b/src/misc.c
@@ -2,12 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/misc.h b/src/misc.h
index cd9261ef..b8b753e6 100644
--- a/src/misc.h
+++ b/src/misc.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/miscfileformats.c b/src/miscfileformats.c
index cc05f7bb..2d67ca3b 100644
--- a/src/miscfileformats.c
+++ b/src/miscfileformats.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018-2019 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Petter Lindquist
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007-2011 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/motoformats.c b/src/motoformats.c
index f8d9b391..2abc3d99 100644
--- a/src/motoformats.c
+++ b/src/motoformats.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018-2019 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Petter Lindquist
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007-2011 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/msxformats.c b/src/msxformats.c
index 449a1ea4..2d66ddb8 100644
--- a/src/msxformats.c
+++ b/src/msxformats.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018-2019 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Petter Lindquist
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007-2011 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/oldies.c b/src/oldies.c
index 4f2c1d68..bec34584 100644
--- a/src/oldies.c
+++ b/src/oldies.c
@@ -2,11 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/oldies.h b/src/oldies.h
index e9abc11e..74985658 100644
--- a/src/oldies.h
+++ b/src/oldies.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2008 Adrien Destugues
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/op_c.c b/src/op_c.c
index 022216f0..845ca02e 100644
--- a/src/op_c.c
+++ b/src/op_c.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2017 Thomas Bernard
-    Copyright 2010 Alexander Filyanov
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/op_c.h b/src/op_c.h
index f81d6024..165ab111 100644
--- a/src/op_c.h
+++ b/src/op_c.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2017 Thomas Bernard
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/operatio.c b/src/operatio.c
index 8bfff4e6..8240507e 100644
--- a/src/operatio.c
+++ b/src/operatio.c
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 2009 Franck Charlet
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/operatio.h b/src/operatio.h
index 6ecb7b98..cbc0925d 100644
--- a/src/operatio.h
+++ b/src/operatio.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/osdep.c b/src/osdep.c
index a4401683..e71df0b6 100644
--- a/src/osdep.c
+++ b/src/osdep.c
@@ -2,12 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2020 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/osdep.h b/src/osdep.h
index 87ffdba9..e3c9b3b1 100644
--- a/src/osdep.h
+++ b/src/osdep.h
@@ -2,12 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2020 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/packbits.c b/src/packbits.c
index 87bf2fa4..aaf624ac 100644
--- a/src/packbits.c
+++ b/src/packbits.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018-2019 Thomas Bernard
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/packbits.h b/src/packbits.h
index 89db71c7..10f8c28e 100644
--- a/src/packbits.h
+++ b/src/packbits.h
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018-2019 Thomas Bernard
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pages.c b/src/pages.c
index ecfe66ab..2d9ec5d7 100644
--- a/src/pages.c
+++ b/src/pages.c
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Franck Charlet
-    Copyright 2007-2017 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pages.h b/src/pages.h
index 827bf384..20acb585 100644
--- a/src/pages.h
+++ b/src/pages.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2011 Pawel Góralski
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/palette.c b/src/palette.c
index 61c02ac0..2bfffbef 100644
--- a/src/palette.c
+++ b/src/palette.c
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007-2017 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/palette.h b/src/palette.h
index 709a537b..77540ae9 100644
--- a/src/palette.h
+++ b/src/palette.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pngformat.c b/src/pngformat.c
index bb7d758e..536523ad 100644
--- a/src/pngformat.c
+++ b/src/pngformat.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Petter Lindquist
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxdouble.c b/src/pxdouble.c
index e5ac538a..53598e54 100644
--- a/src/pxdouble.c
+++ b/src/pxdouble.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxdouble.h b/src/pxdouble.h
index 14810f86..90441cb2 100644
--- a/src/pxdouble.h
+++ b/src/pxdouble.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxquad.c b/src/pxquad.c
index ef88e09e..2f150208 100644
--- a/src/pxquad.c
+++ b/src/pxquad.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxquad.h b/src/pxquad.h
index 04f21950..ce640969 100644
--- a/src/pxquad.h
+++ b/src/pxquad.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxsimple.c b/src/pxsimple.c
index 489e403a..04eda9e7 100644
--- a/src/pxsimple.c
+++ b/src/pxsimple.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxsimple.h b/src/pxsimple.h
index 175d1a65..af31c376 100644
--- a/src/pxsimple.h
+++ b/src/pxsimple.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxtall.c b/src/pxtall.c
index 7818e822..4fe02cf0 100644
--- a/src/pxtall.c
+++ b/src/pxtall.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxtall.h b/src/pxtall.h
index 424ec774..81750a2c 100644
--- a/src/pxtall.h
+++ b/src/pxtall.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxtall2.c b/src/pxtall2.c
index 00950c5d..db691c60 100644
--- a/src/pxtall2.c
+++ b/src/pxtall2.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxtall2.h b/src/pxtall2.h
index 478edf9f..f6e8c5d0 100644
--- a/src/pxtall2.h
+++ b/src/pxtall2.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxtall3.c b/src/pxtall3.c
index bbe64eb4..6d150e75 100644
--- a/src/pxtall3.c
+++ b/src/pxtall3.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxtall3.h b/src/pxtall3.h
index 73570d3c..fa5a7613 100644
--- a/src/pxtall3.h
+++ b/src/pxtall3.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxtriple.c b/src/pxtriple.c
index 4462830e..3fdae3a7 100644
--- a/src/pxtriple.c
+++ b/src/pxtriple.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxtriple.h b/src/pxtriple.h
index 29719cdd..a8ba58b1 100644
--- a/src/pxtriple.h
+++ b/src/pxtriple.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxwide.c b/src/pxwide.c
index 14b7a158..703891f8 100644
--- a/src/pxwide.c
+++ b/src/pxwide.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxwide.h b/src/pxwide.h
index 7ffaf24d..e93c2bc5 100644
--- a/src/pxwide.h
+++ b/src/pxwide.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxwide2.c b/src/pxwide2.c
index e8d2c308..ea776a66 100644
--- a/src/pxwide2.c
+++ b/src/pxwide2.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/pxwide2.h b/src/pxwide2.h
index d6409e97..18edf95e 100644
--- a/src/pxwide2.h
+++ b/src/pxwide2.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/readini.c b/src/readini.c
index bfea47a1..8e86932d 100644
--- a/src/readini.c
+++ b/src/readini.c
@@ -2,11 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Peter Gordon
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/readini.h b/src/readini.h
index 5bc2b5b9..ac4cf00e 100644
--- a/src/readini.h
+++ b/src/readini.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/readline.c b/src/readline.c
index effb00b7..d1043dca 100644
--- a/src/readline.c
+++ b/src/readline.c
@@ -2,11 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2014 Sergii Pylypenko
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/readline.h b/src/readline.h
index 59918427..1b73e1e0 100644
--- a/src/readline.h
+++ b/src/readline.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/realpath.c b/src/realpath.c
index 2c3e4165..2b2c004e 100644
--- a/src/realpath.c
+++ b/src/realpath.c
@@ -69,7 +69,7 @@
         
         if (chdir(path)) {
             if (errno == ENOTDIR) {
-                #if defined(WIN32) || defined(__MORPHOS__) || defined(__amigaos__) || defined(__SWITCH__)
+                #if defined(__MORPHOS__) || defined(__amigaos__) || defined(__SWITCH__)
                     // No symbolic links and no readlink()
                     l = -1;
                 #else
diff --git a/src/realpath.h b/src/realpath.h
index 35f625bc..63151ff9 100644
--- a/src/realpath.h
+++ b/src/realpath.h
@@ -2,7 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Adrien Destugues
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/saveini.c b/src/saveini.c
index b5b6c4d2..c7f92b7e 100644
--- a/src/saveini.c
+++ b/src/saveini.c
@@ -2,12 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2019 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Peter Gordon
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/saveini.h b/src/saveini.h
index 45005242..194f9dcd 100644
--- a/src/saveini.h
+++ b/src/saveini.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/screen.h b/src/screen.h
index 1cf3181d..d0f5c0e4 100644
--- a/src/screen.h
+++ b/src/screen.h
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/sdlscreen.c b/src/sdlscreen.c
index 7ccb5ea5..b4c4a450 100644
--- a/src/sdlscreen.c
+++ b/src/sdlscreen.c
@@ -2,12 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2014 Sergii Pylypenko
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/sdlscreen.h b/src/sdlscreen.h
index 1938c383..a0dc8c3f 100644
--- a/src/sdlscreen.h
+++ b/src/sdlscreen.h
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/setup.c b/src/setup.c
index b4278a59..6fac52e0 100644
--- a/src/setup.c
+++ b/src/setup.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2014 Sergii Pylypenko
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Peter Gordon
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/setup.h b/src/setup.h
index 874d42a6..ffbd4f1b 100644
--- a/src/setup.h
+++ b/src/setup.h
@@ -2,12 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Peter Gordon
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/shade.c b/src/shade.c
index 083c5963..3c907e2a 100644
--- a/src/shade.c
+++ b/src/shade.c
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/shade.h b/src/shade.h
index 94278e55..7a294eb1 100644
--- a/src/shade.h
+++ b/src/shade.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/special.c b/src/special.c
index a03199af..7e460c66 100644
--- a/src/special.c
+++ b/src/special.c
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/special.h b/src/special.h
index 38c1fd45..277da09e 100644
--- a/src/special.h
+++ b/src/special.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/stformats.c b/src/stformats.c
index c1611fc2..d7e5a7e4 100644
--- a/src/stformats.c
+++ b/src/stformats.c
@@ -2,13 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018-2019 Thomas Bernard
-    Copyright 2011 Pawel Góralski
-    Copyright 2009 Petter Lindquist
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2007-2011 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/struct.h b/src/struct.h
index a93eaa70..09f6ff3f 100644
--- a/src/struct.h
+++ b/src/struct.h
@@ -2,11 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2014 Sergii Pylypenko
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/text.c b/src/text.c
index c41ebc63..c66cb3de 100644
--- a/src/text.c
+++ b/src/text.c
@@ -2,12 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2014 Sergii Pylypenko
-    Copyright 2011 Pawel Góralski
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Franck Charlet
-    Copyright 2008 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/text.h b/src/text.h
index d7ee302b..8e8ea792 100644
--- a/src/text.h
+++ b/src/text.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008 Yves Rizoud
-    Copyright 2008 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/tifformat.c b/src/tifformat.c
index 9a9d4557..fd1a9fa1 100644
--- a/src/tifformat.c
+++ b/src/tifformat.c
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/tiles.c b/src/tiles.c
index dd731308..19157b14 100644
--- a/src/tiles.c
+++ b/src/tiles.c
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2011 Yves Rizoud
-    Copyright 2010-2011 Adrien Destugues
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/tiles.h b/src/tiles.h
index 4c4762c4..043eddbb 100644
--- a/src/tiles.h
+++ b/src/tiles.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2011 Yves Rizoud
-    Copyright 2011 Adrien Destugues
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/transform.c b/src/transform.c
index 1c71d3c5..06e5b4e0 100644
--- a/src/transform.c
+++ b/src/transform.c
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2009 Yves Rizoud
-    Copyright 2009 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/transform.h b/src/transform.h
index 9effb757..0fb7c665 100644
--- a/src/transform.h
+++ b/src/transform.h
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2009 Yves Rizoud
-    Copyright 2009 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/unicode.c b/src/unicode.c
index 0af5cdbe..266d6c0c 100644
--- a/src/unicode.c
+++ b/src/unicode.c
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/unicode.h b/src/unicode.h
index 47dd7794..e88e4805 100644
--- a/src/unicode.h
+++ b/src/unicode.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/win32screen.c b/src/win32screen.c
index ed2576ec..03ec7d66 100644
--- a/src/win32screen.c
+++ b/src/win32screen.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/win32screen.h b/src/win32screen.h
index d8db9745..0b2de115 100644
--- a/src/win32screen.h
+++ b/src/win32screen.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/windows.c b/src/windows.c
index 82f8ffda..239fd837 100644
--- a/src/windows.c
+++ b/src/windows.c
@@ -2,9 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2008      Franck Charlet
-    Copyright 2007-2008 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/windows.h b/src/windows.h
index 490bba44..71400622 100644
--- a/src/windows.h
+++ b/src/windows.h
@@ -2,8 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2007-2008 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
diff --git a/src/x11screen.c b/src/x11screen.c
index ecb66da7..f9b2fd32 100644
--- a/src/x11screen.c
+++ b/src/x11screen.c
@@ -2,10 +2,7 @@
 */
 /*  Grafx2 - The Ultimate 256-color bitmap paint program
 
-    Copyright 2018 Thomas Bernard
-    Copyright 2008 Yves Rizoud
-    Copyright 2007 Adrien Destugues
-    Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
+	Copyright owned by various GrafX2 authors, see COPYRIGHT.txt for details.
 
     Grafx2 is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License