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Final Draft: Interpretive Guideline regarding DFSG clause 3


Per recent discussion on the debian-legal mailing list regarding DFSG
section 3 and provisions of documentation-specific licenses that have
been developed in recent years, that allow for non-modifiable portions
of the work (such as the license text itself) and mandate the display of
certain text on the outside surfaces of physical media, I am proposing a
guideline for interpretation of the DFSG that clarifies the criteria
that a license must meet to satisfy the DFSG.


The following clause of the Debian Free Software Guidelines should be
kept in mind when reading my proposal.  Also consider that that my
proposed guidelines are only that; any generally perceived conflict
between the DFSG and my guidelines must be resolved in favor of the DFSG
until and unless the DFSG is amended.  These guidelines are proposed and
intended as a "gentlemen's agreement" to clarify certain areas rendered
ambiguous by the DFSG or by current practice in the Debian Project.

It is helpful to review the text of clauses 3 of the Debian Free
Software Guidelines.

DFSG Clause 3: Derived Works

The license must allow modifications and derived works, and must allow
them to be distributed under the same terms as the license of the
original software.

For further reading:

The Debian Free Software Guidelines ("DFSG") and Social Contract:

The GNU General Public License ("GNU GPL"):

The GNU Free Documentation License ("GNU FDL"):

The Open Publication License ("OPL"):

Previous debian-legal discussion:
...and most of the subsequent traffic for the month, spilling over into


1) A copyright holder is permitted to withhold permission to modify or
remove copyright notices upon a work, or parts of a work, under
copyright by that holder.  Permission to modify or remove copyright
notices not used as such (i.e., as examples), or which are irrelevant
due to the absence of any material under copyright by that holder, must
not be withheld.

2) A copyright holder is permitted to withhold permission to modify or
remove license texts which apply to a work, or to a substantively
related work.  Permission to modify or remove license texts which are
not used as such (i.e., as examples), or which are irrelevant due to the
absence of material under that license within that work, or a
substantively related one, must not be withheld.  Permission must be
granted to include or exclude the text of the license in alternative
formats or duplicate copies, as long as at least one copy of each
applicable license text accompanies the work as part of the Debian
GNU/Linux Distribution.


Impact of this proposal:

1) Works licensed under existing, widely-used, understood-as-DFSG-free
licenses still meet the DFSG.  The GNU GPL, GNU LGPL, Artistic License,
MIT/X Consortium license, and 2-, 3-, and 4-clause[*] forms of the BSD
license are unaffected.

[*] The 4-clause BSD license is not affected because the unmodifiable
text in the advertising clause is not part of the work itself, but part
of the license.  In theory, advertising materials that are part of a
work licensed under the 4-clause BSD license would not be DFSG-free,
except that compliance with the DFSG is easily achieved by removing any
such advertising materials from the work, as is permitted by the
remainder of the license.  Furthermore, little software is licensed
under the 4-clause BSD terms anymore: see

2) Works licensed under the OPL meet the DFSG if and only if neither of
the license options listed in section 6 of the OPL are exercised.

3) Works licensed under the GNU FDL meet the DFSG if:
   A) there are no Invariant Sections[*]; or
   B) the only Invariant Sections consist of license texts which
      apply to a work, or a substantively related work (such as the
      program being documented, in the case of a manual).

[*] Cover Texts are not affected for the same reason that the 4-clause
BSD advertising clause is not: the unmodifiable text is only
unmodifiable outside the work as distributed as part of the Debian
GNU/Linux Distribution, which is not a "printed copy", and is the scope
of the DFSG.  Some readings of the DFSG regard Cover Texts as a
violation of clause 6 of the DFSG; this proposal takes no position on
that argument.

4) Works licensed under the traditional GNU documentation license, which

   Permission is granted to make and distribute verbatim copies of this
   manual provided the copyright notice and this permission notice are
   preserved on all copies.

   Permission is granted to copy and distribute modified versions of
   this manual under the conditions for verbatim copying, provided that
   the entire resulting derived work is distributed under the terms of a
   permission notice identical to this one.

   Permission is granted to copy and distribute translations of this
   manual into another language, under the above conditions for modified
   versions, except that this permission notice may be stated in a
   translation approved by the Free Software Foundation.

meet the DFSG.

While this is not a Policy proposal or a General Resolution, and thus
does not require seconds, I am seeking seconds for this proposal as a
means of gauging its level of acceptance.

G. Branden Robinson                |     You could wire up a dead rat to a
Debian GNU/Linux                   |     DIMM socket and the PC BIOS memory
branden@debian.org                 |     test would pass it just fine.
http://people.debian.org/~branden/ |     -- Ethan Benson

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