Clarify GPL-3 vs. GPL-3-or-any-later-version
The copyright boilerplate in the source files (e.g. Src/siesta.F
) is very terse:
! Copyright (C) 1996-2016 The SIESTA group
! This file is distributed under the terms of the
! GNU General Public License: see COPYING in the top directory
! or http://www.gnu.org/copyleft/gpl.txt .
! See Docs/Contributors.txt for a list of contributors.
It does not say which version of the GPL (though COPYING
in the top directory has GPL-3 as content), but crucially, it does not mention whether SIESTA is strictly under the GPL-3 or (as is usually preferred) under the GPL-3 "or any later version" (also, 2016 might be outdated as upper Copyright bound, but I did not check every source file).
The general best practice would be to spell this out explicitly in the copyright boilerplate, like
! Copyright (C) 1996-2016 The SIESTA group
! This file is distributed under the terms of the
! GNU General Public License version 3 or (at your
! option) any later version. See COPYING in the top
! directory or http://www.gnu.org/licenses/gpl-3.0.txt .
! See Docs/Contributors.txt for a list of contributors.