For better or (more likely) worse, copyright now automatically encumbers every new fixed work of authorship. Copyright kicks in as soon as anyone writes an essay, doodles a sketch, or bangs out an email. A copyright's holder need not register the work or put notices on copies of it to qualify for copyright protection.
If you want to play it safe, you should thus probably assume that some sort of copyright claim binds every fixed work. Even very old works often come with modern copyright strings attached. Consider, for instance, John Stuart Mill's classic work, On Liberty. Though the book originally issued in 1859, and has long since fallen into the public domain, my library's copy includes a notice reading, "Copyright 1978 by Hackett Publishing Company, Inc." Presumably, that copyright covers only the editor's introduction and selected bibliography. Yet Hackett's overbroad notice doubtless discourages some people—especially those who know little about copyright law—from reproducing even the free parts of On Liberty.
In that and other ways, copyright policy currently fails to admit to its limitations. Cautiously presuming that copyright covers every fixed work, and duped by inflated copyright notices, we fail to fully enjoy our rights to the public domain. We should aspire to a more open copyright system, one that encourages both the creation of new works and the liberation of extant ones. For that, we need a way to signal, clearly and reliably, when a work has escaped the bounds of copyright. We need, in other works, an uncopyright notice.
The Copyright Act provides that copyright holders can brand their works with "Copyright," or "Copr.," in lieu of the copyright symbol, "©." An uncopyright notice would naturally read "Uncopyright" or "Uncopr." The uncopyright symbol? A "©" overlaid with a backslash, per the international iconography of things forbidden. In cases where such graphics prove too troublesome, the cents character in parentheses—"(¢)"—would do nicely.
Where will uncopyrighted works come from? Some will come from clearly unprotected parts of the public domain. The worthy Project Gutenberg, for instance, offers favorite old texts on the web, unencumbered with copyright protection, in an easily-accessed format. New works, too, might carry "(¢)" marks, put there by authors eager to help build the public domain.
[NB: The above text comes from part of my draft book, Intellectual Privilege: Copyright, Common Law, and the Common Good. Specifically, it comes from a portion of the draft of Part III, Chapter 7: Uncopyright and Open Copyright. You can find a complete draft of the full chapter, together with footnotes, here [PDF]. I welcome your comments.]
[Crossposted to Intellectual Privilege and The Technology Liberation Front.]