One of the rights accorded to the owner of  copyright is the right to  reproduce or to authorize others to reproduce  the work in copies or  phonorecords. This right is subject to certain  limitations found in  sections 107 through 118 of the copyright law (
title 17, U. S. Code).   One of the more important limitations is the doctrine of “fair use.”   The doctrine of fair use has developed through a substantial number of   court decisions over the years and has been codified in section 107 of   the copyright law. 
 Section 107 contains a list of the various purposes for which the   reproduction of a particular work may be considered fair, such as   criticism, comment, news reporting, teaching, scholarship, and research.   Section 107 also sets out four factors to be considered in determining   whether or not a particular use is fair: 
 
-  The purpose and  character of the use, including whether such  use is of commercial  nature or is for nonprofit educational purposes
 
-  The nature of the copyrighted work
 
-  The amount and substantiality of the portion used in relation to the copyrighted work as a whole
 
-  The effect of the use upon the potential market for, or value of, the copyrighted work
 
  
  The distinction between fair use and infringement may be unclear and   not easily defined. There is no specific number of words, lines, or   notes that may safely be taken without permission. 
 Acknowledging the source of the copyrighted material does not substitute for obtaining permission. 
 The 1961 Report of the Register of Copyrights on the General Revision  of the U.S. Copyright Law cites 
examples of activities that courts have  regarded as fair use: “quotation  of excerpts in a review or criticism  for purposes of illustration or  comment; quotation of short passages in a  scholarly or technical work,  for illustration or clarification of the  author’s observations;  use in a parody of some of the content of the  work parodied; summary  of an address or article, with brief quotations,  in a news report;  reproduction by a library of a portion of a work to  replace part of a  damaged copy; reproduction by a teacher or student of a  small part of a  work to illustrate a lesson; reproduction of a work in  legislative or  judicial proceedings or reports; incidental and  fortuitous  reproduction, in a newsreel or broadcast, of a work located  in the  scene of an event being reported.” 
 Copyright protects the particular way an author has expressed  himself.  It does not extend to any ideas, systems, or factual  information  conveyed in the work. 
 The safest course is always to get permission from the copyright  owner  before using copyrighted material. The Copyright Office cannot  give  this permission. 
 When it is impracticable to obtain permission, use of copyrighted   material should be avoided unless the doctrine of fair use would clearly   apply to the situation. The Copyright Office can neither determine if a   certain use may be considered fair nor advise on possible copyright   violations. If there is any doubt, it is advisable to consult an   attorney. 
 FL-102, Revised May 2009