Clarify licensing, thanks to @musicinmybrain (Ben Beasley). Fixes #30.

Signed-off-by: Stephen L. <lrq3000@gmail.com>

LICENSE

@@ -1,2 +1,42 @@
-Released to the public domain. Original implementation can be found at
-http://en.wikiversity.org/wiki/Reed%E2%80%93Solomon_codes_for_coders
+The software is available under your choice of
+Unlicense (SPDX short identifier: Unlicense) or
+MIT No Attribution License (SPDX short identifier: MIT-0):
+
+-----
+
+<<START OF UNLICENSE>>
+This is free and unencumbered software released into the public domain.
+
+Anyone is free to copy, modify, publish, use, compile, sell, or
+distribute this software, either in source code form or as a compiled
+binary, for any purpose, commercial or non-commercial, and by any
+means.
+
+In jurisdictions that recognize copyright laws, the author or authors
+of this software dedicate any and all copyright interest in the
+software to the public domain. We make this dedication for the benefit
+of the public at large and to the detriment of our heirs and
+successors. We intend this dedication to be an overt act of
+relinquishment in perpetuity of all present and future rights to this
+software under copyright law.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+For more information, please refer to <http://unlicense.org/>
+<<END OF UNLICENSE>>
+
+-----
+
+<<START OF MIT-0 LICENSE>>
+Copyright 2013-2023 Tomer Filiba & Stephen Larroque
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+<<END OF MIT-0 LICENSE>>

README.rst

@@ -344,9 +344,7 @@ For a list of all contributors, please see `the GitHub Contributors graph <https
 License
 -------
 
-This software is released to the Public Domain.
-
-If the Public Domain is not adequate for your purpose, you can instead consider this module under the MIT License as you prefer.
+This software is released under your choice of the Unlicense or the MIT-0 (MIT No Attribution) License. Both licenses are `public-domain-equivalent licenses <https://en.wikipedia.org/wiki/Public-domain-equivalent_license>`_, as intended by the original author Tomer Filiba.
 
 
 .. |PyPI-Status| image:: https://img.shields.io/pypi/v/reedsolo.svg

setup.py

@@ -45,23 +45,25 @@
     extensions = None
 
 setup(name = "reedsolo",
-    version = "1.6.0",
+    version = "1.6.1",
     description = "Pure-Python Reed Solomon encoder/decoder",
     author = "Tomer Filiba",
     author_email = "tomerfiliba@gmail.com",
     maintainer = "Stephen Karl Larroque",
     maintainer_email = "lrq3000@gmail.com",
-    license = "Public Domain",
+    license = "Public Domain",  # the license field can only store one license, use classifiers below to declare multiple licenses https://github.com/pypi/warehouse/issues/8960
     url = "https://github.com/tomerfiliba/reedsolomon",
     py_modules = ["reedsolo"],
     platforms = ["any"],
     long_description = open("README.rst", "r").read(),
     long_description_content_type = 'text/x-rst',
+    license_files = ('LICENSE',),  # force include LICENSE file, requires setuptools >= 42.0.0. Note that this field only support one line text, do not input the full license content here. The full LICENSE file is currently forcefully included via MANIFEST.in, but other methods exist, see: https://stackoverflow.com/a/66443941/1121352
     classifiers = [
         "Development Status :: 6 - Mature",
         "Intended Audience :: Developers",
         "Intended Audience :: Information Technology",
-        "License :: OSI Approved :: MIT License",
+        "License :: OSI Approved :: The Unlicense (Unlicense)",  # Unlicense OR MIT-0 at the user preference
+        "License :: OSI Approved :: MIT No Attribution License (MIT-0)",
         'Operating System :: Microsoft :: Windows',
         'Operating System :: MacOS :: MacOS X',
         'Operating System :: POSIX :: Linux',