Legal Dictionary

public domain

Legal Definition of public domain



Related terms

Definition of public domain


public domain (uncountable)

  1. The feature of intellectual property being not protected under patent or copyright, i.e. no person or other legal entity can establish proprietary interests.

    "This book is in public domain"

  2. Open land such as unowned prairie in the western and southwestern United States. Space not subject to a land patent.
  3. Information about a subject which is accessible to anyone

    "There is very little information about the treaty which is in the public domain."


public domain (comparative more public domain, superlative most public domain)

  1. Not subject to any copyright or patent restrictions.

Further reading


In a general context, public domain may refer to ideas, information, and works that are "publicly available", but in the context of intellectual property law (which includes copyright, patents, and trademarks), public domain refers to works, ideas, and information which are intangible to private ownership and/or which are available for use by members of the public.

Defining the public domain

Definitions of the boundaries of the public domain in relation to copyright, or intellectual property more generally, regard the public domain as a negative space, that is, it consists of works that are no longer in copyright term or were never protected by copyright law. According to James Boyle this definition underlines common usage of the term public domain and equates the public domain to public property and works in copyright to private property. However, the usage of the term public domain can be more granular, including for example uses of works in copyright permitted by copyright exceptions. Such a definition regards work in copyright as private property subject to fair use rights and limitation on ownership. A conceptual definition comes from Lange, who focused on what the public domain should be: "it should be a place of sanctuary for individual creative expression, a sanctuary conferring affirmative protection against the forces of private appropriation that threatened such expression". Patterson and Lindberg described the public domain not as a "territory", but rather as a concept: "There are certain materials - the air we breathe, sunlight, rain, space, life, creations, thoughts, feelings, ideas, words, numbers - not subject to private ownership. The materials that compose our cultural heritage must be free for all to use no less than matter necessary for biological survival." The term public domain may also be interchangeably used with other imprecise and/or undefined terms such as the "public sphere" or "commons", including concepts such as "commons of the mind", the "intellectual commons", and the "information commons".

Value of public domain

In attempting to map the public domain Pamela Samuelson has identified eight "values" that can arise from information and works in the public domain, though not every idea or work that is in the public domain necessarily has a value. Possible values include:

  • Building blocks for the creation of new knowledge, examples include data, facts, ideas, theories, and scientific principle.
  • Access to cultural heritage through information resources such as ancient Greek texts and Mozart's symphonies.
  • Promoting education, through the spread of information, ideas, and scientific principles.
  • Enabling follow-on innovation, through for example expired patents and copyright.
  • Enabling low cost access to information without the need to locate the owner or negotiate rights clearance and pay royalties, through for example expired copyrighted works or patents, and non-original data compilation.
  • Promoting public health and safety, through information and scientific principles.
  • Promoting the democratic process and values, through news, laws, regulation, and judicial opinion.
  • Enabling competitive imitation, through for example expired patents and copyright, or publicly disclosed technologies that do not qualify for patent protection.



1.     doctrine of stare decisis
2.     legal system
3.     civil law
4.     minimum contacts
5.     adjudication order
6.     abscond
7.     AORO
8.     just compensation
9.     precedent
10.     warrants