It appears that Battle for Wesnoth is considering changing their policy
in regards to which licenses are allowed in their add-ons repository.
Here is a briefing of the situation (from a conversation in #fsf IRC
channel, only joins/quits and unrelated messages were removed):
--8<---cut here---start->8---
2017-08-12T14:09-0300 Hi.
2017-08-12T14:09-0300 It looks like Wesnoth developers will
allow non-free add-ons.
2017-08-12T14:09-0300 ?
2017-08-12T14:09-0300 Proof?
2017-08-12T14:09-0300
https://forums.wesnoth.org/viewtopic.php?f=6=46093
2017-08-12T14:10-0300 any CC = with non-free
2017-08-12T14:10-0300 Remove it from Free Software Directory
[...]
2017-08-12T14:13-0300 Not exactly non-free per see... But *can* pose
some issues to GNU FSDG compliant distros.
2017-08-12T14:13-0300 The GNU FSDG is somewhat strictier in regards
to what is allowed in free distros.
[...]
2017-08-12T14:14-0300 Wesnoth's UMC licensing change does pose an
issue because this means that the third-party repository will no longer be
commited to comply with the GNU FSDG.
2017-08-12T14:14-0300 third-party = UMC
2017-08-12T14:14-0300 But downloader is included into Wesnoth.
2017-08-12T14:15-0300 *add-ons downloader
2017-08-12T14:18-0300 This probably means that GNU FSDG-compliant
distros will have to modify the "add-ons downloader" so as not to download
from UMC.
2017-08-12T14:24-0300 Can you report this on some mailing
lists?
[...]
2017-08-12T14:35-0300 Will do.
[...]
2017-08-12T14:49-0300 Is there a mailing list for issues like
this?
[...]
2017-08-12T14:55-0300 temp_trisquel: I guess the main point is
gnu-linux-libre:
[[https://lists.nongnu.org/mailman/listinfo/gnu-linux-libre]] (group's main
page: [[https://libreplanet.org/wiki/FreedSoftware]])
2017-08-12T14:56-0300 But, it also helps to simply drop a link to the
thread in gnu-linux-libre, in development mailing lists for GNU FSDG distros
(guix-devel, and so oon). :)
[...]
2017-08-12T14:58-0300 I'll post to gnu-linux-libre now.
--8<---cut here---end--->8---
The basis for my argumentation is that, according to GNU FSDG, section
about license rules
([[https://www.gnu.org/distros/free-system-distribution-guidelines.html#license-rules]]):
#+BEGIN_QUOTE
“Information for practical use” includes software, documentation, fonts,
and other data that has direct functional applications. It does not
include artistic works that have an aesthetic (rather than functional)
purpose, or statements of opinion or judgment.
All information for practical use in a free distribution must be
available in source form. (“Source” means the form of the information
that is preferred for making changes to it.)
The information, and the source, must be provided under an appropriate
free license. We evaluate specific licenses and list our determinations
in our license list, with separate sections for licenses that are
suitable for software, documentation, fonts, and other useful works. If
such a work is released under a disjunction of licenses, the work is
free as long as at least one of its licenses is free; the system
developers should follow the terms of the applicable free license(s)
when they distribute and/or modify it.
A free system distribution must not steer users towards obtaining any
nonfree information for practical use, or encourage them to do so. The
system should have no repositories for nonfree software and no specific
recipes for installation of particular nonfree programs. Nor should the
distribution refer to third-party repositories that are not committed to
only including free software; even if they only have free software
today, that may not be true tomorrow. Programs in the system should not
suggest installing nonfree plugins, documentation, and so on.
#+END_QUOTE
The rule of not referencing to third-party repositories commited to the
GNU FSDG, however, seens to only apply to functional/practical
data/works.
Furthermore, the GNU FSDG mentions, in the section about non-functional
data
([[https://www.gnu.org/distros/free-system-distribution-guidelines.en.html#non-functional-data]]):
#+BEGIN_QUOTE
Data that isn't functional, that doesn't do a practical job, is more of
an adornment to the system's software than a part of it. Thus, we don't
insist on the free license criteria for non-functional data. It can be
included in a free system distribution as long as its license gives you
permission to copy and redistribute, both for commercial and
non-commercial purposes. For example, some game engines released under
the GNU GPL have accompanying game information—a fictional world map,
game graphics, and so on—released under such a verbatim-distribution
license. This kind of data can be part of a free system distribution,
even though its license does not qualify as free, because it is
non-functional.
#+END_QUOTE
So far, I have made some basic empirical observation how Battle for
Wesnoth's
