This library is provided to everyone under the GNU LESSER GENERAL PUBLIC
LICENSE (version 2.1). The test programs are licensed under the BSD Zero Clause
License. All source files are tagged accordingly using SPDX syntax.

To contribute to libpwm patches/commits need to certify that they are provided
under the same license as the modified files. To do so, add a sign-off line at
the end of the commit log, which certifies that you wrote it or otherwise have
the right to pass it on as an open-source patch. The semantic follows how
contributions are handled in the Linux kernel. So iff you can certify the below:

------------->8----------------
Developer's Certificate of Origin 1.1

By making a contribution to this project, I certify that:

(a) 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; or

(b) The contribution is based upon previous work that, to the best
    of my knowledge, is covered under an appropriate open source
    license and I have the right under that license to submit that
    work with modifications, whether created in whole or in part
    by me, under the same open source license (unless I am
    permitted to submit under a different license), as indicated
    in the file; or

(c) The contribution was provided directly to me by some other
    person who certified (a), (b) or (c) and I have not modified
    it.

(d) I understand and agree that this project and the contribution
    are public and that a record of the contribution (including all
    personal information I submit with it, including my sign-off) is
    maintained indefinitely and may be redistributed consistent with
    this project or the open source license(s) involved.
------------->8----------------

then you just add a line saying::

	Signed-off-by: Random J Developer <random@developer.example.org>

.