The exceptions and limitations to the otherwise exclusive rights of a copyright holder.
While copyright is usually conceptualized as the granting of a monopoly for a limited period of time, there are nearly always exceptions and limitations to the otherwise exclusive rights of a copyright holder. These can be statutory or customary, and represent uses for which a user need not get permission, or for which fees are preset, or something else that places limits on the monopoly of the copyright holder. These exceptions and limitations are often driven by public policy concerns.
“Fair use” in U.S. law and “fair dealing” in some other parts of the world, are classic examples of doctrines that place a limitation on the copyright holder’s monopoly. Any form of compulsory licensing would be another. Some exceptions are directed at particular classes of user, such as the exceptions pertaining to making copies for the disabled.
Rule-based
Rule-based exceptions are those whose qualities are described in specific detail, so that a particular use either does or does not qualify as an exception.
The Chaffee Amendment in U.S. Copyright law that exempts the making of copies for the disabled is an example of a rule-based exception.
Guideline-based
A guideline-based exception or limitation is one that sets forth one or more factors to consider when determining whether a particular use is fair, rather than hard and fast bright-line rules.
Any particular use must be evaluated on an individual basis to determine if it qualifies for the exception. For example, the “fair use” doctrine in U.S. law, which lists four non-exhaustive factors and partial list of suggested fair uses, is a guideline-based exception.
Library exceptions
Libraries are often treated as a special sub-class of users of copyrighted material because of the public nature of their mission and the strong public policy arguments in their favor. As such, they enjoy a unique set of exceptions and limits on copyright law in many countries. While the copyright law concerning libraries varies from country to country, there are some near-universal general exceptions for libraries.
Preservation
Libraries are frequently permitted to make copies of works in order to preserve them, or for archival purposes, without violating the copyright in those works.
This is in line with the traditional role of libraries as repositories of knowledge.
Loaning
Under certain circumstances, libraries are permitted to make copies of copyrighted works for the purpose of loaning them to patrons or to other libraries without violating the copyright in those works.
Research
Libraries are often permitted to make copies of copyrighted works for research purposes (whether their own or that of their patrons) without violating the copyright in those works.