"Based on the new guidelines posted by the SFLC on 'Maintaining Permissive-Licensed Files in a GPL-Licensed Project: Guidelines for Developers', specifically section 5, we are introducing a new tag for use with patches which deal with files licensed under permissive licenses (BSD, ISC) on Linux wireless in our larger GPL project, the Linux kernel," explained Luis Rodriguez in an email titled, "new 'Changes-licensed-under' tag introduced for Linux-wireless". The web pages linked in the email appear to be an official response by the SFLC regarding the recent BSD vs. GPL licensing controversy surrounding the Atheros wireless device driver. Luis continued:

"Although some developers have a practice of implying their patches for a permissive licensed file abides by the respective permissive license of the file being patched, and although some changes are obviously not copyrightable, we would like to 'err on the side of caution', take the advice from SFLC, and introduce Changes-licensed-under in order to help the BSD family reap benefits of our contributions to permissive licensed files."

There were only a few brief replies to Luis' email. Stephen Hemminger suggested a simpler solution, "no, please don't [go] down this legal rat hole. It would cause bullshit like people submitting dual licensed patches to the scheduler or GPL only patches to the ath5k or ACPI code. Instead, add a section to Documentation/SubmittingPatches that clearly states that all changes to a file are licensed under the same license as the original file." Krzysztof Halasa pointed out that this was already the case, quoting a line from the Developer's Certificate of Origin contained in the SubmittingPatches file which says, "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".

During the continuing debates regarding the legality and fairness of re-licensing BSD licensed code, it was asked why the BSD license couldn't be extracted from Windows applications known to include BSD licensed code. OpenBSD creator Theo de Raadt explained, "what you ran strings on is not 'source code'. It was the binary," pointing to the first clause of the BSD license used by the code in question which says, "redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer." He then quoted the second clause of the BSD license, "redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution," and added, "if you take your Microsoft documentation, and dig really deep, you will find the whole notice copied into it there. Go ahead, you'll find it."

Theo continued, explaining that earlier versions of the BSD license used in OpenBSD and other BSD projects still had the advertising clause which required all advertising materials for products using their code to include a notice stating, "this product includes software developed by the University of California, Berkeley and its contributors." He added, "and.. once again, older copies of Windows DID follow that rule, too, just like Sun and everyone else," noting that one exception was AT&T and the Unix System Laboratories, "who included modified BSD manuals in their Unixware commercial distributions, and that mistake resulted in USL losing the USL v BSDI & University of California lawsuit. (I have simplified the situation, s/losing/settling at a serious loss/)."

OpenBSD project creator Theo de Raadt detailed his concerns regarding BSD-licensed code and Dual-BSD/GPL-licensed code being re-licensed under only the GPL as previously discussed here, "honestly, I was greatly troubled by the situation, because even people like Alan Cox were giving other Linux developers advice to ... break the law. And furthermore, there are even greater potential risks for how the various communities interact." He went on to add:

"It may seem that the licenses let one _distribute_ it under either license, but this interpretation of the license is false -- it is still illegal to break up, cut up, or modify someone else's legal document, and, it cannot be replaced by another license because it may not be removed. Hence, a dual licensed file always remains dual licensed, every time it is distributed."

Theo then talked about cases where a significant amount of code is added or changed, "if you add 'large pieces of originality' to the code which are valid for copyright protection on their own, you may choose to put a different and separate (must be non-conflicting...) license at the top of the file above the existing license." He then suggested, "if you wish for everyone to remain friends, you should give code back. That means (at some ethical or friendliness level) you probably do not want to put a GPL at the top of a BSD or ISC file, because you would be telling the people who wrote the BSD or ISC file, 'thanks for what you wrote, but this is a one-way street, you give us code, and we take it, we give you you nothing back.'"