Legally "all rights reserved" is the default, until/unless you follow the legally appropriate ceremony to disable it. If you get the ceremony wrong in some way

Legally "all rights reserved" is the default, until/unless you follow the legally appropriate ceremony to disable it. If you get the ceremony wrong in some way then you're back to "all rights reserved" in practice, regardless of intent. CC0 contains the lawyer-developed appropriate ceremony to do what you want here, including handling weird jurisdictions. The way you've phrased it will confuse the lawyers and may or may not "work" legally speaking. There are instructions on the CC site about how to apply CC0 to a project. CC0 was developed for precisely this purpose.