A provision of the Copyright Act that entitles anyone to quote or cite protected material in literary review, educational instruction, scholarly research, editorial opinion, news report, comparative advertisment, or parody without infringement or permission. Any extensive excerpts or qualitative collections must be authorized for use, reprint, or release by the copyright or trademark owner. Factors to be considered when determining whether to apply the Fair Use doctrine include purpose and character of the use, nature of copyrighted work, amount and substantiality of portion used, and effect of use on potential copyright market. While every commercial use is "presumptively unfair", that presumption is easily overcome by productive or transformative, nonsuperseding use, a secondary use that produced a new result or purpose, different from the original ... the commercial character of song parody does not create presumption against fair use. In order to prevail on the effect on the market for the copyrighted work element, on alleged copyright infringer's contention of fair use, copyright owner is only required to show that challenged use, should it become widespread, would adversely affect potential market for copyrighted work. Certain nonprofit uses can qualify as fair use, even though they may involve nonproductive superseding copies. See public domain, plagiarism, appropriation, subsidiary rights, volume rights, specialized format.