Limitations and exceptions to copyright

Two important examples of limitations and exceptions to copyright are the fair use doctrine found in the United States, and the fair dealing doctrine found in many other common law countries. Other limitations and exceptions include the public domain and Crown copyright issues of ownership. As well, the underlying rationale of copyright is always subject to interpretation, i.e. when is some particular fixation of knowledge or information covered by copyright and when is it just information, most encyclopedias, dictionaries and other reference works such as Wikipedia operate on the principle that knowledge and information are not subject to copyright as they are part of our common human culture and heritage.

The scope of copyright limitations and exceptions is currently a subject of significant controversy within various nations, largely due to the impact of digital technology, and the enactment of anti-circumvention rules[?] in response to the WIPO Copyright Treaty. Defenders of copyright exemptions fear that DRM technology will massively reduce the scope of important exceptions. Their opponents believe that if existing exemptions are allowed to continue, they will necessarily allow huge amounts of private copying[?] and/or piracy-- if consumers can make a copy of a CD for their car, they can give MP3s to the everyone.

Limitations and exceptions are also the subject of significant regulation by international treaties. These treaties have harmonized the exclusive rights which must be provided by copyright laws, and the Berne three-step test operates to constrain the kinds of copyright exceptions and limitations which individual nations can enact.

On the other hand, international copyright treaties place almost no requirements on national goverments to provide exemptions from exclusive rights (one notable exception to this is Article 10(1) of the Berne Convention, which guarantees a limited right to make quotations from copyrighted works).