Public domain

Public domain comprises the body of knowledge and innovation (especially creative works such as writing, art, music, and inventions) in relation to which no person or other legal entity can establish or maintain proprietary interests within a particular legal jurisdiction. This body of information and creativity is considered to be part of a common cultural and intellectual heritage, which, in general, anyone may use or exploit, whether for commercial or non-commercial purposes. Only about 15 percent of all books are in the public domain, and 10 percent of all books are still in print.

If an item ("work") is not in the public domain, this may be the result of a proprietary interest such as a copyright, patent, or other sui generis right. The extent to which members of the public may use or exploit the work is limited to the extent of the proprietary interests in the relevant legal jurisdiction. However, when the copyright, patent or other proprietary restrictions expire, the work enters the public domain and may be used by anyone for any purpose.

No legal restriction on use
A creative work is said to be in the public domain if there are no laws which restrict its use by the public at large. For instance, a work may be in the public domain if no laws establish proprietary rights over the work, or if the work or its subject matter are specifically excluded from existing laws.

Because proprietary rights are founded in national laws, an item may be public domain in one jurisdiction but not another. For instance, some works of literature are public domain in the US but not in the EU and vice versa.

The underlying idea which is expressed or manifested in the creation of a work generally cannot be the subject of copyright law (see idea-expression divide). Mathematical formulas will therefore generally form part of the public domain, to the extent that their expression in the form of software is not covered by copyright; however, algorithms can be the subject of a software patent in some jurisdictions.

Works created before the existence of copyright and patent laws also form part of the public domain. The Bible and the inventions of Archimedes are in the public domain. However, copyright may exist in translations or new formulations of these works.

Although "intellectual property" laws are not designed to prevent facts from entering the public domain, collections of facts organized or presented in a creative way, such as categorized lists, may be copyrighted. Collections of data with intuitive organization, such as alphabetized directories like telephone directories, are generally not copyrightable. In some countries copyright-like rights are granted for databases, even those containing mere facts. A sui generis database rights regime is in place in the European Union.

Works of the United States Government and various other governments are excluded from copyright law and may therefore be considered to be in the public domain.

Creative Commons, an organization which promotes the migration of works into the public domain as well as copyleft licensing schemes, holds that:


 * Public access to literature, art, music, and film is essential to preserving and building on our cultural heritage.

Expiration
All copyrights and patents have always had a finite term, though the terms for copyrights and patents differ. When terms expire, the work or invention is released into public domain. In most countries, patents expire 20 years after they are filed. A trademark registration may be renewed and remain in force indefinitely provided the trademark is used, but could otherwise become generic.

Copyrights are more complex than patents; generally, in current law, the copyright in a published work expires in all countries when all of the following conditions are satisfied (except Colombia, Cote d'ivoire, Guatemala, Honduras, Mexico, Samoa, and Saint Vincent and the Grenadines, on all these countries are fair use): These conditions are based on the intersection of United States and European Union copyright law, which most other Berne Convention signatories recognize. Note that copyright term extension under U.S. tradition usually does not restore copyright to public domain works (hence the 1923 date), but European tradition does because the EU harmonization was based on the copyright term in Germany, which had already been extended to life plus 70.
 * The work was created and first published before January 1, 1923, or at least 95 years before January 1 of the current year, whichever is later;
 * The last surviving author died at least 70 years before January 1 of the current year;
 * No Berne Convention signatory has passed a perpetual copyright on the work; and
 * Neither the United States nor the European Union has passed a copyright term extension since these conditions were last updated. (This must be a condition because the exact numbers in the other conditions depend on the state of the law at any given moment.)

United States law
In the United States, copyright law has changed several times since the founding of the country. It is held under Feist v. Rural that Congress does not have the power to re-copyright works that have fallen into the public domain. Eldred v. Ashcroft transcript However, re-copyrighting has happened before. "After World War I and after World War II, there were special amendments to the Copyright Act to permit for a limited time and under certain conditions the recapture of works that might have fallen into the public domain, principally by aliens of countries with which we had been at war." (Testimony of Dorothy Schrader, general counsel of the U.S. copyright office, hearing for H.R. 1623, serial 100/50)

Works created by an agency of the United States government are public domain at the moment of creation. Examples include military journalism, federal court opinions (but not necessarily state court opinions), congressional committee reports, and census data. However, works commissioned by the government but created by a contractor are still subject to copyright, and even in the case of public domain documents, availability of such documents may be limited by laws limiting the spread of classified information.

Before 1978, unpublished works were not covered by the federal copyright act. This does not mean that the works were in the public domain. Rather, it means that they were covered under (perpetual) state copyright law. The claim that "pre-1923 works are safe" is only correct for published works; unpublished works are under federal copyright for at least the life of the author plus seventy years. If they were created before 1978 but first published before 2002, the works have federal copyright protection until 2047.

The public domain began to receive widespread attention after David Lange's seminal law review article, "Recognizing the Public Domain," which was published in volume forty-four of Law & Contemporary Problems in 1981.

Until the Berne Convention Implementation Act of 1988, the lack of a proper copyright notice would force an otherwise copyrightable work into the public domain, although for works published between 1978 and 1989, this defect could be cured by registering the work with the Library of Congress within 5 years of publication. After 1988, an author's copyright in a work begins when it is fixed in a tangible form; neither publication nor registration is required, and a lack of a copyright notice does not place the work into the public domain.

Critics of copyright term extensions have said that Congress has achieved a perpetual copyright term "on the installment plan." Statement of Professor Peter Jaszi, The Copyright Term Extension Act of 1995: Hearing on S.483 Before the Senate Judiciary Comm., 104th Cong.

British law
British government works are restricted by either Crown Copyright or Parliamentary Copyright. Published Crown Copyright works become public domain at the end of the year 50 years after they were published, unless the author of the work held copyright and assigned it to the Crown. In that case, the copyright term is the usual life of author plus 70 years. Unpublished Crown Copyright documents become public domain at the end of the year 125 years after they were first created. However, under the legislation that created this rule, and abolished the traditional common law perpetual copyright of unpublished works, no unpublished works will become public domain until 50 years after the legislation came into effect. Since the legislation became law on 1 August 1989, no unpublished works will become public domain under this provision until 2039. Parliamentary Copyright documents become public domain at the end of the year 50 years after they were published. Crown Copyright is waived on some government works provided that certain conditions are met.

Laws of Canada, Australia, and Other Commonwealth Nations
These numbers reflect the most recent extensions of copyright in the United States and Europe. Canada and New Zealand have not, as of 2006, passed similar twenty-year extensions. Consequently, their copyright expiry times are still life of the author plus 50 years. Australia passed a 20-year copyright extension in 2004, but delayed its effect until 2005, and did not make it revive already-expired copyrights. Hence, in Australia works by authors who died before 1955 are still in the public domain.

As a result, works ranging from Peter Pan to the stories of H. P. Lovecraft are public domain in both countries. (The copyright status of Lovecraft's work is debatable, as no copyright renewals, which were necessary under the laws of that time, have been found. Also, two competing parties have independently claimed copyright ownership on his work.)

As with most other Commonwealth of Nations countries, Canada and Australia follow the general lead of the United Kingdom on copyright of government works. Both have a version of Crown Copyright which lasts for 50 years from publication. New Zealand also has Crown Copyright, but has a much greater time length, at 100 years from the date of publication. India has a government copyright of sixty years from publication, to coincide with its somewhat unusual life of the author plus sixty years term of copyright.

Thai law
According to Thai copyright law, the copyright term is the life of author plus 50 years. When the author is a legal entity or an anonymous person, the copyright term is 50 years from the date of publication. Works of applied art (defined as drawings/paintings, sculpture, prints, architecture, photography, and drafts) have a copyright term of 50 years from publication. Republication of works after the expiration of the copyright term does not reset the copyright term. Thai state documents are public domain.

Examples
Examples of inventions whose patents have expired include the inventions of Thomas Edison. Examples of works whose copyrights have expired include the works of Carlo Collodi, Mozart, and most of the works of Mark Twain, excluding the work first published in 2001, A Murder, a Mystery, and a Marriage. In the United States, Frank Capra's classic film, It's a Wonderful Life (1946) was put into the public domain in 1974, because someone inadvertently failed to file a copyright renewal application with the Copyright Office during the 28th year after the film's release or publication. It wasn't until 1993 when Republic Pictures relied on the 1990 United States Supreme Court ruling in Stewart v. Abend to enforce its claim of copyright of the film. As a result, only NBC is currently licensed to show the film on U.S. network television, the colorized versions have been withdrawn and Republic got exclusive video rights to the film (under license with Artisan Entertainment). Rights to It's a Wonderful Life now belong to Paramount Pictures.

Currently four shorts by the Three Stooges are in the public domain due to accidental failure to renew their copyrights in the 60s. These are Disorder In The Court, Brideless Groom, Malice In The Palace, and Sing a Song of Six Pants. Other features and films from the Stooges are known to be in public domain as well.

Several Episodes of The Lucy Show are similarly in the public domain.

Some works may never fully lapse into the public domain, such as the play Peter Pan by J. M. Barrie. While the copyright of this work expired in the United Kingdom in 1987, it has been granted special treatment under the Copyright, Designs and Patents Act 1988 (Schedule 6) that requires certain royalties to be paid for performances within the UK, so long as Great Ormond Street Hospital continues to exist.

Disclaimer of interest
Laws may make some types of works and inventions ineligible for monopoly; such works immediately enter the public domain upon publication. Many kinds of mental creations, such as publicized baseball statistics, are never covered by copyright. However, any special layout of baseball statistics, or the like, would be covered by copyright law. For example, while a phonebook is not covered by copyright law, any special method of laying out the information would be.

For example: U.S. copyright law, 17 U.S.C. § 105, releases all works created by the U.S. government into the public domain. U.S. patent applications containing a copyright notice must also include a disclaimer of certain exclusive rights as part of the terms of granting the patent to the invention (leaving open the question regarding copyright of patents with no such notice). Agreements that Germany signed at the end of World War I released such trademarks as "aspirin" and "heroin" into the public domain in many areas.

Another example would be Charles Darwin's theory of evolution. Being an abstract idea it has therefore never been patentable. After Darwin constructed his theory, he did not disclose it for over a decade (see Development of Darwin's theory). He could have kept his manuscript in his desk drawer forever but once he published the idea, the idea itself entered public domain. However, the carrier of his ideas, in the form of a book titled The Origin of Species, was covered by copyright (though, since he died in 1882, the copyright has since expired).

Copyright
In the past, in some jurisdictions such as the USA, a work would enter the public domain with respect to copyright if it was released without a copyright notice. This was true prior to March 1, 1989 (according to the USA Copyright office), but is no longer the case. Any work (of certain, enumerated types) receives copyright as soon as it is fixed in a tangible medium.

It is commonly believed by non-lawyers that it is impossible to put a work into the public domain. Although copyright law generally does not provide any statutory means to "abandon" copyright so that a work can enter the public domain, this does not mean that it is impossible or even difficult, only that the law is somewhat unclear. Congress may not have felt it necessary to codify this part of the law, because abandoning property (like a tract of land) to the public domain has traditionally been a matter of judge-made law, rather than statute. (Alternatively, because copyright has traditionally been seen as a valuable right, one which required registration to achieve, it would not have made sense to contemplate someone abandoning it in 1976 and 1988.)

Computer Software Rental Amendments Act
There are several references to putting copyrighted work into the public domain. The first reference is actually in a statute passed by Congress, in the Computer Software Rental Amendments Act of 1990 (H.R. 5498 of the 101st Congress). Although most of the Act was codified into Title 17 of the U.S. Code, there is a very interesting provision relating to "public domain shareware" which was not, and is therefore often overlooked.

'Sec. 105. Recordation of Shareware'

(a) IN GENERAL- The Register of Copyrights is authorized, upon receipt of any document designated as pertaining to computer shareware and the fee prescribed by section 708 of title 17, United States Code, to record the document and return it with a certificate of recordation.

''(b) MAINTENANCE OF RECORDS; PUBLICATION OF INFORMATION- The Register of Copyrights is authorized to maintain current, separate records relating to the recordation of documents under subsection (a), and to compile and publish at periodic intervals information relating to such recordations. Such publications shall be offered for sale to the public at prices based on the cost of reproduction and distribution.''

(c) DEPOSIT OF COPIES IN LIBRARY OF CONGRESS- In the case of public domain computer shareware, at the election of the person recording a document under subsection (a), 2 complete copies of the best edition (as defined in section 101 of title 17, United States Code) of the computer shareware as embodied in machine-readable form may be deposited for the benefit of the Machine-Readable Collections Reading Room of the Library of Congress.

''(d) REGULATIONS- The Register of Copyrights is authorized to establish regulations not inconsistent with law for the administration of the functions of the Register under this section. All regulations established by the Register are subject to the approval of the Librarian of Congress.''

One purpose of this legislation appears to be to allow "public domain shareware" to be filed at the Library of Congress, presumably so that the shareware would be more widely disseminated. Therefore, one way to release computer software into the public domain might be to make the filing and pay the $20 fee. This could have the effect of "certifying" that the author intended to release the software into the public domain. It does not seem that registration is necessary to release the software into the public domain, because the law does not state that public domain status is conferred by registration. Judge-made law supports this conclusion, see below.

By comparing paragraph (a) and (c), one can see that Congress distinguishes "public domain" shareware as a special kind of shareware. Because this law was passed after the Berne Convention Implementation Act of 1988, Congress was well aware that newly created computer programs (two years worth, since the Berne Act was passed) would automatically have copyright attached. Therefore, one reasonable inference is that Congress intended that authors of shareware would have the power to release their programs into the public domain. This interpretation is followed by the Copyright Office in 37 C.F.R. § 201.26.

Berne Convention Implementation Act
The Berne Convention Implementation Act of 1988 states in section twelve that the Act "does not provide copyright protection for any work that is in the public domain." The congressional committee report explains that this means simply that the Act does not apply retroactively. Some interest groups lobbied heavily to make the Act retroactive in order to increase the U.S.'s negotiating leverage with other countries, because the U.S. often asks developing countries to allow the copyrighting of previously public-domain work.

Although the only part of the act that does mention "public domain" does not speak to whether authors have the right to dedicate their work to the public domain, the remainder of the committee report does not say that they intended copyright should be an indestructible form of property. Rather the language speaks to getting rid of formalities in order to comply with Berne (non-compliance had become a severe impediment in trade negotiations) and making registration and marking optional, but encouraged. A fair reading is that the Berne Act did not intend to take away author's right to dedicate works to the public domain, which they had (by default) under the 1976 Act.

Section 203 of the Copyright Act
Although there is support in the statutes for allowing work to be dedicated to the public domain, there cannot be an unlimited right to dedicate work to the public domain because of a quirk of U.S. copyright law which grants the author of a work the right to cancel "the exclusive or nonexclusive grant of a transfer or license of copyright or of any right under a copyright" thirty-five years later, unless the work was originally a work for hire. 

It is unsettled how this section would mesh with a purported public domain dedication. Any of these interpretations are possible:
 * No effect. Any holder of a copyright can release it to the public domain. This interpretation is probably wrong, because then an author would lose the right to his "termination right," which in practical terms means a royalty. To prevent paying the royalty, a comic book company could release the copyright to the public domain but hold onto the trademark, which would suffice to prevent knock-off comics from being made. Because the Captain America case (Marvel v. Simon) showed that this termination right cannot be alienated before death, this interpretation is almost certainly wrong.
 * Some effect. An author may release his own work into the public domain, and a company holding a work for hire may release his work into the public domain. But a company which has purchased a copyright from an author (as was the case with most of the "Golden Age" comic book writers) cannot. Although the distinction of allowing an author to release his own work is not explicit in the statute, it may not be literally inconsistent (it is not a "transfer" or a "license," and it arguably is not a grant of a right under copyright), and this reading is necessary to comply with the 1990 Act discussed above, as well as the case law discussed below.
 * Strong effect. Only a company holding a work for hire can release the work into the public domain. Because of the references to "shareware" (above) and "programmers" (below), and the fact that many software companies in the 1980s were quite small (and thus did not have employees), this reading seems inconsistent with the intent of Congress.

Case law
Another form of support comes from the seminal case Computer Associates Int'l v. Altai, 982 F.2d 693. This case set the standard for determining copyright infringement of computer software and is still followed today. Moreover, it was decided by the Second Circuit appellate court, which is famous for handing down some of the most well-reasoned American copyright decisions. In this case, it discusses the public domain.

(c) Elements Taken from the Public Domain

''Closely related to the non-protectability of scenes a faire, is material found in the public domain. Such material is free for the taking and cannot be appropriated by a single author even though it is included in a copyrighted work. ... We see no reason to make an exception to this rule for elements of a computer program that have entered the public domain by virtue of freely accessible program exchanges and the like. See 3 Nimmer Section 13.03 [F] ; see also Brown Bag Software, slip op. at 3732 (affirming the district court’s finding that “‘[p]laintiffs may not claim copyright protection of an . . . expression that is, if not standard, then commonplace in the computer software industry.’“). Thus, a court must also filter out this material from the allegedly infringed program before it makes the final inquiry in its substantial similarity analysis.''

This decision holds that computer software may enter the public domain through "freely accessible program exchanges and the like," or by becoming "commonplace in the computer industry." Relying only on this decision, it is unclear whether an author can dedicate his work to the public domain simply by labeling it as such, or whether dedication to the public domain requires widespread dissemination.

This could make a distinction in a CyberPatrol-like case, where a software program is released, leading to litigation, and as part of a settlement the author assigns his copyright. If the author has the power to release his work into the public domain, there would be no way for the new owner to stop the circulation of the program. A court may look on an attempt to abuse the public domain in this way with disfavor, particularly if the program has not been widely disseminated. Either way, a fair reading is that an author may choose to release a computer program to the public domain if he can arrange for it to become popular and widely disseminated.

Treatise analysis
The treatise cited (Nimmer), holds in its most recent edition:

13.03[F][4]

''It is axiomatic that material in the public domain is not protected by copyright, even when incorporated into a copyrighted work. ...''

''An enormous amount of public domain software exists in the computer industry, perhaps to a much greater extent than is true of other fields. Nationwide computer "bulletin boards" permit users to share and distribute programs. In addition, computer programming texts may contain examples of actual code that programmers are encouraged to copy.''

''Programmers often will build existing public domain software into their works. The courts thus must be careful to limit protection only to those elements of the program that represent the author's original work.''

Although Computer Associates only mentioned the issue in passing, Nimmer observes that the public domain is particularly rich and valuable for computer programs. He seems to say that a computer program author who wishes to release his work into the public domain may either include it in a book as example code or post it on a "bulletin board" and encourage sharing and distribution. (Nimmer is the treatise most widely cited in copyright opinions, and is generally authoritative.)

Non-equivalence of licenses
For various reasons, including the uncertainty in international law, the fear of liability suits, and of course the not-quite-settled state of U.S. law, licenses have become popular as a substitute for dedicating work to the public domain. Such a license would grant permission for all of the acts which are restricted by copyright law. Such a license is sometimes called a "public-domain equivalent license," which is somewhat of a misnomer.

There are several ways in which this license does not substitute for a true public domain release.

Revocability where no consideration
A "bare license" unsupported by consideration is (theoretically) revocable at will. A license, generally in the law, is permission to do something that would ordinarily be a trespass. For example, when a friend is invited to a home for coffee, the friend has a license to remain in the house. The friend can be kicked out of the house at any time. However, if the friend has paid money and signed a contract to live in the house for a month, he has the right to stay.

Revocability is not a problem in practice for two reasons. Entities which release software (such as M.I.T. and the University of California) are generally disinclined to be obnoxious. Second, there are certain legal defenses which could be raised, such as an "implied license by legal estoppel," if the original license purported to be perpetual, or the flimsier defense of equitable estoppel otherwise. However, most licenses, even the "public-domain equivalent" licenses, do not purport to be perpetual. The M.I.T license, for example, does not.

A "bare license" of free software has been revoked in the past. Simply because a friendly entity released a program under a license does not mean that the friendly entity will continue to hold the copyright in the future. In the well-known CyberPatrol case, the defendants settled in part by transferring the offending program to a hostile party. The hostile party immediately revoked the GPL license of the program. (As a general rule, licenses are revocable, and the GPL does not purport to be perpetual.) His solution is to rely on 17 USC 205(e), which holds:

''(e) Priority Between Conflicting Transfer of Ownership and Nonexclusive License. — A nonexclusive license, whether recorded or not, prevails over a conflicting transfer of copyright ownership if the license is evidenced by a written instrument signed by the owner of the rights licensed or such owner’s duly authorized agent, and if — '' (1) the license was taken before execution of the transfer; or (2) the license was taken in good faith before recordation of the transfer and without notice of it.

To do so, someone signs a license to a friendly party, like the FSF, which, in his theory, preserves the GPL license to the world forever. (He observes that under other federal law, this can be done electronically, despite the language saying "written instrument signed.") It is certainly possible that Eben Moglen's interpretation would be upheld in court, but the case would be far from a slam-dunk, especially in a case like CyberPatrol where the new copyright holder has good reason to want the license revoked.

The problem with Eben Moglen's interpretation comes from the unique construction of the GPL. The GPL purports to grant a new license from the original grantor, rather than each succeeding author of a program granting a sub-license to the next. By the very terms of the statute, however, licenses from the original licensor are only protected if the license was granted before executing the transfer. (New licenses from the original licensor are not allowed, because the original licensor no longer holds the copyright to the work.) Therefore, further distribution of a GPL program is significantly limited after GPL is revoked. To be precise, the current holders of the program are authorized to modify and distribute the software, if they hold a "written instrument signed by the [former] owner," but the recipients of the software may not further redistribute it.

Verbiage
The license will usually contain language perpetuating itself, of several kinds of wording. It can be unclear what license applies to what part of the work, increasing the likelihood that provisions pertaining to certain parts of the work will be breached. Outside the context of computer software, it may not even be possible to use a license due to excess verbiage. Magazine publishers might acquiesce to an author's request of putting a public domain notice on, say, a magazine article, but not allow several column inches to be filled with license boilerplate.

Privity problems
An unfortunate problem with proliferating licenses is privity. In short, when a user has rights under a sub-license, they come only from the person who sub-licensed the work to him. It does not matter on what terms that person licensed the work. For instance, the original person may have paid money to receive extra commercialization rights. The book Open Source Licensing by Lawrence Rosen explains that virtually all open-source licenses use a "sub-licensing" model, where each user's rights come from the person who gave him that copy. The GPL is one of the very few that purports to issue rights from the original licensor.

It is well-settled that work in the public domain keeps that status, even after being embedded in a copyrighted work. (See Nimmer above.) So that work can be extracted and used in another work. But if a liberally-licensed work has been included in a software program with a draconian license, it is not possible to legally extract the liberally-licensed work from the program, unless the license is an unusual one which purports not to sub-license. All of the user's rights flow from the license under which he received the program; it is irrelevant whether the previous person was subject to a more lenient license.

Instead the user must find the original, liberally-licensed work and take from that. For example, the original 4.4BSD lite release was missing several important files and would not run directly. Suppose that the developers who made the software work chose to release the software under a harsher license which imposes restrictions against commercialization, rather than preserving the original license. Now suppose 10 years later someone wants to use some code from BSD in a commercial program. It might be impossible to track down an original copy of 4.4BSD lite, but strictly speaking they are not permitted to take even original BSD code out of the modern version.

Moral rights
Under section 6bis of the Berne copyright treaty, authors have so-called moral rights which are inalienable. These rights give an author the right of attribution (even in parts copied under "fair use") and the right not to have his work defaced. More generally, the civil law moral rights are the disclosure right, paternity right, integrity right, retraction right, retirement right and the right to the honor.

The U.S., generally speaking, rejects the notion of inalienable moral rights. Other countries, notably France, forbid authors signing away their moral rights in advance.

"Public domain equivalent licenses" are not at all equivalent in some countries outside the United States because authors cannot write language into their licenses that would guarantee users that they would not be sued in the future by the author. Contributors to controversial works, like Linda Lovelace, have repudiated their earlier views as they grew older. It is not enough for an author to give assurances that he approves of any use of his work, because he may change his mind and sue.

Even inside the United States, there may be a Dastar Corp. v. Twentieth Century Fox Film Corp. problem with a mere license. A work's being in the public domain prevents former copyright holders from asserting related actions under the Lanham Act or state law. A mere license would not necessarily cut off these related actions unless the license were written very carefully.

Moral rights do not cause difficulty with computer software licenses, because civil law countries have made special statutory exceptions where, absent agreement to the contrary, an author may not object to the modification of a software work by a grantee who has acquired the right to adapt the work. (Source: French Copyright Law revision of July 3, 1985, art. 46. See Ginsburg, Reforms and Innovations Regarding Authors' and Performers' Rights in France: Commentary on the Law of July 3, 1985, 10 Colum.-VLA J.L. & Arts 83, 90 (1985))

Patent
With regards to patents, on the other hand, public use or publishing the details of an invention before applying for a patent will generally place an invention in the public domain and (in theory) prevent its subsequent patenting by anyone – - an effective disclaimer. For example, a chemistry journal publishing a formula prevents patenting the formula by anyone. This tactic was commonly used by Bell Labs. The famous Bell Labs Technical Journal was sent free of charge to the library of the U.S. Patent Office to establish a base of prior art without the inconvenience, cost, and hassle of filing patent applications for inventions of no immediate monetary value. (Unix was famously described in this journal.) This is sometimes called "defensive disclosure" - one way to make sure you are not later accused of infringing a patent on your own invention. There is an exception to this rule, however: in U.S. (not European) law, an inventor may file a patent claim up to one year after publishing a description (but not, of course, if someone else published or used it first).

In practice, patent examiners only consider other patents and the books they have in their library for prior art, largely because the patent office has an elaborate classification system for inventions. This means that an increasing number of issued patents may be invalid, based upon prior art that was not brought to the examiner's attention. Once a patent is issued, it is very expensive to invalidate. Publishing a description on a website as a pre-emptive disclosure does very little in a practical sense to release an invention to the public domain; it might still be considered "patentable", although erroneously. However, anyone aware of an omitted prior art citation in an issued patent may submit it to the US Patent Office and request a "reexamination" of the patent during the enforceable period of the patent (i.e., its life plus statute of limitions). This may result in loss of some or all of the patent protection of the invention, or it may backfire and actually strengthen the claims.

An applicant may also choose to file a Statutory Invention Registration, which has the same effect as a patent for prior art purposes. These SIRs are relatively expensive. These are used strategically by large companies to prevent competitors from obtaining a patent.

Section 102(c) says that an invention that has been "abandoned" cannot be patented. There is precious little case-law on this point. It is largely a dead letter.

If an inventor has an issued patent, there are several ways to release it to the public domain (other than simply letting it expire). First, he can fail to pay the maintenance fee the next time it is due, about every four years. Alternatively he can file a terminal disclaimer under 37 CFR 1.321 for a reasonable fee. The regulations explicitly say that the "patentee may disclaim or dedicate to the public the entire term, or any terminal part of the term, of the patent granted. Such disclaimer is binding upon the grantee and its successors or assigns." Usually this is used during the application process to protect another patent from a "double-patenting" invalidation. Lastly, he may grant a patent license to the world, although the issue of revocability may raise its head again.

Trade secret
If guarded properly, trade secrets are forever. A business may keep the formula to Coca-Cola a secret. However, once it is disclosed to the public, the former secret enters public domain, although an invention using the former secret may still be patentable in the United States if it is not barred by statute (including the on-sale bar).

Some businesses choose to protect products, processes, and information by guarding them as trade secrets, rather than patenting them. Hershey Foods, Inc., for example, does not patent some of its processes, such as the recipe for Reese's, but rather maintains them as trade secrets, to prevent competitors from easily duplicating or learning from their invention disclosures.

One risk, however, is that anyone may reverse engineer a product and thus discover (and copy and publish) all of its secrets, to the extent they are not protected by other laws (e.g., patent, contract).

Trademark
A trademark registration is renewable. If a trademark owner wishes to do so, he may maintain a registration indefinitely by paying renewal fees, using the trademark and defending the registration.

However, a trademark or brand can become unenforceable if it becomes the generic term for a particular type of product or service -- a process called "genericide." If a mark undergoes genericide, people are using the term generically, not as a trademark to exclusively identify the particular source of the product or service. One famous example is "thermos" in the United States.

Because trademarks are registered with governments, some countries or trademark registries may recognize a mark, while others may have determined that it is generic and not protectable as a trademark in that registry. For example, the drug "salicylic acid" (2-acetoxybenzoic acid), is better known as aspirin in the United States -- a generic term. In Canada, however, "aspirin" is still a trademark of the German company Bayer. Bayer lost the trademark after World War I, when the mark was sold to an American firm. So many copycat products entered the marketplace during the war that it was deemed generic just three years later.

Terms can be deemed "generic" in two ways. First, any potential mark can be deemed "generic" by a trademark registry, that refuses to register it. In this instance, the term has no secondary meaning that helps consumers identify the source of the product; the term serves no function as a "mark". Second, a mark, already in use, may be deemed generic by a court or registry after the mark is challenged as generic--this is known as "genericide". In this instance, the term previously had a secondary meaning, but lost its source-identifying function.

To avoid "genericide", a trademark owner must balance between trying to dominate the market, and dominating their market to such an extent that their product name defines the market. A manufacturer who invents an amazing breakthrough product which cannot be succinctly described in plain English (for example, a vacuum-insulated drinking flask) will inevitably find its product described by the trademark ("Thermos"). If the product continues to dominate the market, eventually the trademark will become generic ("thermos").

However, "genericide" is not an inevitable process. In the late 1980s "Nintendo" was becoming synonymous with home video game consoles but Nintendo was able to reverse this process through marketing campaigns. Xerox was also successful in avoiding its name becoming synonymous with the act of photocopying (although, in some languages (Russian) and countries (like India), it became generic).

Trademarks currently thought to be in danger of being generic include Jello, Band-Aid, Rollerblading, Google, Spam, Hoover, and Sheetrock. Google vigorously defends its trademark rights. Although Hormel has resigned itself to genericide, it still fights attempts by other companies to register "spam" as a trademark in relation to computer products.

When a trademark becomes generic, it is as if the mark were in the public domain.

Trademarks which have been genericized in particular places include: Escalator, Trampoline, Raisin Bran, Linoleum, Dry Ice, Shredded Wheat (generic in US), Mimeograph, Yo-Yo, Kerosene, Cornflakes, Cube Steak, Lanolin, and High Octane, (Source: Xerox ad, reprinted in Copyright, Patent, Trademark, ..., by Paul Goldstein, 5th ed., p. 245) as well as Aspirin (generic in the United States, but not in Canada), Allen wrench, Beaver Board, Masonite, Coke, Pablum, Styrofoam, Heroin, Bikini, Chyron, Weedwhacker, Kleenex, Linux (generic in Australia) and Zipper.

Domain name
People may buy and sell domain names. Sometimes, people advertise them as their own "intellectual property". In early 2000, the record-breaker domain name "business.com" was sold for $8 million.

A domain name never enters public domain. If nobody owns it, it simply doesn't exist. Top level domains, such as .com, are controlled by the ICANN (Internet Corporation for Assigned Names and Numbers). A domain name is sometimes described as a lease, but this has only a shred of truth in it. In fact it is much closer to a trademark. While a leaseholder of, say, real estate cannot be ejected from the property by anybody (except the government, in rare cases), domain names are subject to cybersquatting suits and trademark suits.

Public domain and the Internet
The term "public domain" is often poorly understood and has created significant legal controversy. Historically, most parties attempting to address public domain issues fell into two camps:
 * 1) Businesses and organizations who could devote staff to resolving legal conflicts through negotiation and the court system.
 * 2) Individuals and organizations using materials covered by the fair use doctrine, reducing the need for substantial governmental or corporate resources to track down individual offenders.

With the advent of the Internet, however, it became possible for anybody with access to this worldwide network to "post" copyrighted or otherwise-licensed materials freely and easily. This aggravated an already established but false belief that, if something is available through a free source, it must be public domain. Once such material was available on the net, it could be perfectly copied among thousands or even millions of computers very quickly and essentially without cost.

Freely obtained does not mean free to republish
These factors have reinforced the false notion that "freely obtained" means "public domain". One could argue that the Internet is a publicly-available domain, not licensed or controlled by any individual, company, or government; therefore, everything on the Internet is public domain. This specious argument ignores the fact that licensing rights are not dependent on the means of distribution or consumer acquisition. (If someone gives a person stolen merchandise, it is still stolen, even if the receiving party was not aware of it.) Chasing down copyright violations based on the idea that information is inherently free has become a primary focus of industries whose financial structure is based on their control of the distribution of such media. Though this is legally correct, public support for these companies' efforts is significantly undermined by the belief that they are receiving their "just deserts" for decades of price-gouging for licensed media. Ironically, this puts many creators of such work, like musicians and authors, on both sides of the issue, since they have frequently fought media distributors over inadequate compensation for their work, but depend on distributors' revenues for that compensation.

(Almost) everything written down is copyrighted
Another complication is that publishing exclusively on the Internet has become extremely popular. According to U.S. law, at least, an author's original works are covered by copyright, even without a formal notice incorporated into the work. But such laws were passed at a time when the focus was on materials that could not be as easily and cheaply reproduced as digital media, nor did they comprehend the ultimate impossibility of determining which set of electronic bits is original. Technically, any Internet posting (such as blogs or emails) could be considered copyrighted material unless explicitly stated otherwise.

The distribution of many types of Internet postings (particularly Usenet articles and messages sent to electronic mailing lists) inherently involves duplication. The act of posting such a work can therefore be taken to imply consent to a certain amount of copying, as dictated by the technical details of the manner of distribution. However, it does not necessarily imply total waiver of copyright.

Furthering the public domain with the Internet
Many people are using the Internet to contribute to the public domain, or make works in the public domain more accessible to more people. For example, Project Gutenberg and LibriVox coordinate the efforts of people who transcribe works in the public domain into electronic form. Some projects exist for the sole purpose of making material available into the public domain or under no-cost licences.

Note that there are many works that are not part of the public domain, but for which the owner of some proprietary rights has chosen not to enforce those rights, or to grant some subset of those rights to the public. See, for example, the Free Software Foundation which creates copyrighted software and licenses it without charge to the public for most uses under a class of license called "copyleft", forbidding only proprietary redistribution. Wikipedia does much the same thing with its content under the GNU Free Documentation License. Sometimes such work is inadvertently referred to as "public domain" in colloquial speech.

Note also that while some works (especially musical works) may be in the public domain, U.S. law considers performances or (some) transcriptions of those works to be derivative works, potentially subject to their own copyrights. Similarly, a film adaptation of a public-domain story (such as a fairy tale or a classic work of literature) may itself be copyrightable.

Reference

 * Fishman, Stephen, The Public Domain: How to Find & Use Copyright-Free Writings, Music, Art & More. ISBN 0-87337-433-9