@lacabra we can discuss the concept of public domain dedication vs licensing in a separate topic. It should be a basic human freedom / right to dedicate a work into public domain with no implied fears or questions asked. Lawyers I know could consult people why CC-0 is bad for code and why The Unlicense may not be suitable for art according to copyright law. But defending public domain as an alternative to copyright requires a different approach. Forcing people to choose SPDX for CC-0, Unlicense, WTFPL or any other license equivalent instead of opting out from copyright may leaves an impression that everybody is happy about the copyright, but that is not true. And as more projects include SPDX validators and ask for valid license identifiers, we dilute and lose the voice of people who would prefer the public domain to be a simple and convenient tool to release their work without the defaults of responsibility and legal knowledge that is imposed by the copyright law.