Adopt consistent format for Copyright notices

[keith-zephyr]

Introduction

The contributor guidelines instruct developers to follow the Linux foundation best practices for copyrights in open source projects.

Problem description

Zephyr isn't following the Linux foundation recommendation. Some contributors always update the copyright, many others only include a copyright message on the first commit.

Proposed change

Adopt a standard Copyright message for Zephyr. One of

Copyright (c) YYYY The Zephyr Project Authors
Copyright (c) YYYY The Zephyr Project Contributors
Copyright (c) YYYY Zephyr Project Members

The first 2 options come from the Linux foundation. The 3rd option has limited use in the tree now (15 results)

[keith-zephyr]

If this is adopted, we would not remove any existing copyright notices in the tree, per the LF recommendation.

• New files would include the Zephyr Project copyright and optionally the author's own copyright.
• When modifying files, the Zephyr Project copyright is appended to the existing copyright notice for the file.

[keith-zephyr]

Another discussion topic is the Copyright year format. The Zephyr tree shows the following patterns:

Copyright (c) 2019
Copyright (c) 2022-2024
Copyright (c) 2017, 2019
Copyright (c) 2011-2012, 2014-2015

I propose we recommend only including the current year in the copyright notice. When amending a a file, there is no need to update the date in copyright notice. Authors are free to add a new copyright line.

For US copyright, only the year of the first publication is needed.

[henrikbrixandersen]

Are you suggesting we require contributors to sign over copyright of their work to the Linux Foundation? If so, why?

[nashif]

Are you suggesting we require contributors to sign over copyright of their work to the Linux Foundation? If so, why?

where is this being suggested?

The recommendation of the LF clearly state:

...
These statements are intended to communicate the following:

- the work is copyrighted;
- the contributors of the code licensed it, but retain ownership of their copyrights; and
- it was licensed for distribution as part of the named project.
...

Proposed change

Adopt a standard Copyright message for Zephyr. One of

Copyright (c) YYYY The Zephyr Project Authors
Copyright (c) YYYY The Zephyr Project Contributors

This one matches the recommendation, but I would recommend keeping it simple without years and (c), because this is the reason you want to go this route. notices being out of date all the time and also different companies using (c) in different ways and formats, so keep it simple and just foillow the recommendation to the letter.

Copyright (c) YYYY Zephyr Project Members

please no, member has a special meaning in this context, ie. being a member of the project (silver, platinum, etc.)

[keith-zephyr]

This one matches the recommendation, but I would recommend keeping it simple without years and (c), because this is the reason you want to go this route. notices being out of date all the time and also different companies using (c) in different ways and formats, so keep it simple and just foillow the recommendation to the letter.

I agree with this. I opened this issue after seeing a PR author change the copyright year in an existing file. If we drop the year, then it's easier for compliance checks to enforce the format as well.

[keith-zephyr]

Are you suggesting we require contributors to sign over copyright of their work to the Linux Foundation? If so, why?

As Anas noted, no one signs over copyright with this proposal. The github history is still the authoritative source of truth for copyright.

[henrikbrixandersen]

Are you suggesting we require contributors to sign over copyright of their work to the Linux Foundation? If so, why?

As Anas noted, no one signs over copyright with this proposal. The github history is still the authoritative source of truth for copyright.

Sounds good, sorry I misread the proposal initially. The whole "Zephyr Project Members" threw me off, as that is a distinct group of LF/Project member companies (as already pointed by @nashif). We need our documentation to be very clear about the fact, that there is no copyright reassignment, as this is known to cause contribution issues at least for some companies.

Personally, I'd prefer the consistent copyright notice to say "The Zephyr Project Contributors" as "contributor" is already a well-established term in the Zephyr community (see e.g. https://docs.zephyrproject.org/latest/contribute/index.html).

[jfischer-no]

"Copyright The XYZ Author" should not be optional, but always required when adding a new file to the project. It is established practice and does not contradict https://www.linuxfoundation.org/blog/blog/copyright-notices-in-open-source-software-projects.