/usr/share/doc/prerex/copyright is in prerex 6.5.4-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 | This work was packaged for Debian by:
    Ryan Kavanagh <ryanakca@kubuntu.org> on Wed, 14 Sep 2011 08:31:45 2011 -0400
It was originally downloaded from:
    ftp://linus.cs.queensu.ca/prerex/
It is currently downloaded from:
    https://ctan.org/tex-archive/graphics/prerex
Upstream Author:
    R. D. Tennent <rdt@cs.queensu.ca>
Copyright:
    Copyright (C) 2006-2017 R. D. Tennent <rdt@cs.queensu.ca>
License:
 This package is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.
  
 This package 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 this program. If not, see <http://www.gnu.org/licenses/>
  
On Debian systems, the complete text of the GNU General
Public License version 2 can be found in "/usr/share/common-licenses/GPL-2".
The Debian packaging is:
    Copyright (C) 2011–2017 Ryan Kavanagh <rak@debian.org>
you can redistribute it and/or modify it under the terms of the GNU General
Public License as published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
 |