The copyright symbol, or copyright sign, designated by © (a circled capital letter "C"), is the symbol used in copyright notices for works other than sound recordings (which are indicated with the ℗ symbol). The use of the symbol is described in United States copyright law, and, internationally, by the Universal Copyright Convention. The C stands for copyright.
The copyright notice required by the U.S. Copyright Acts used to be a prescribed, lengthy formula: "Entered according to act of Congress, in the year , by A. B., in the office of the Librarian of Congress, at Washington." In general, this notice had to appear on the copyrighted work itself, but in the case of a "work of the fine arts", such as a painting, it could instead be inscribed "on the face of the substance on which [the work of art] shall be mounted". The Copyright Act was amended in 1874 to allow a much shortened notice: "Copyright, 18 , by A. B."
The Copyright Act of 1909 was meant to be a complete rewrite and overhaul of existing copyright law. As originally proposed in the draft of the bill, copyright protection required putting the word "copyright" or a sanctioned abbreviation on the work of art itself, also for paintings, the argument being that the frame was detachable. In conference sessions among copyright stakeholders on the proposed bill, conducted in 1905 and 1906, representatives of artist organizations objected to this requirement, wishing to put no more on the work itself than the artist's name. As a compromise, the possibility was created to add a relatively unintrusive mark, the capital letter C within a circle, to appear on the work itself next to the artist's name, indicating the existence of a more elaborate copyright notice elsewhere that was still to be allowed to be placed on the mounting. Indeed, the version of the bill that was submitted to Congress in 1906, compiled by the Copyright Commission under the direction of the Librarian of Congress, Herbert Putnam, contained a provision that a special copyright symbol, the letter C inclosed within a circle, could be used instead of the word "copyright" or the abbreviation "copr.", but only for a limited category of copyrightable works, including works of art but not ordinary books or periodicals. The formulation of the 1909 Act was left unchanged when it was incorporated in 1946 as title 17 of the United States Code; when that title was amended in 1954, the symbol © was allowed as an alternative to "Copyright" or "Copr." in all copyright notices.
In countries party to the Berne Convention for the Protection of Literary and Artistic Works, including the modern-day U.S., a copyright notice is not required to be displayed in order for copyright to be established; rather, the creation of the work automatically establishes copyright.
US copyright notice 
- the © symbol, or the word "Copyright" or abbreviation "Copr.";
- the year of first publication of the copyrighted work; and
- an identification of the owner of the copyright, either by name, abbreviation, or other designation by which it is generally known.
© 2011 John Smith
The notice was once required in order to receive copyright protection in the United States, but in countries respecting the Berne convention this is no longer the case. The United States joined the Berne Convention in 1989.
Digital representation 
The character is mapped in Unicode as U+00A9 © copyright sign (HTML:
©). Unicode also has U+24B8 Ⓒ circled latin capital letter c (HTML:
Ⓒ) and U+24D2 ⓒ circled latin small letter c (HTML:
ⓒ). They are sometimes used as a substitute copyright symbol where the actual copyright symbol is not available in the font or in the character set, for example, in some Korean code pages.
On Windows it may be entered by holding the Alt while typing the numbers 0 1 6 9 on the numeric keypad. It can be entered on a Mac by holding the Option key and then pressing the "g" key. On Linux, it can be obtained with the <compose key> O C ComposeKey sequence.
Related symbols 
- The sound recording copyright symbol is the symbol ℗ (the capital letter P enclosed by a circle), and is used to designate copyright in a sound recording.
- The copyleft symbol is a backwards capital letter C in a circle (copyright symbol © mirrored). Because it is unavailable on Unicode, it can be approximated with character U+2184 ↄ latin small letter reversed c between parentheses (ↄ) or, if supported by the application, by combining it with the character U+20DD ⃝ combining enclosing circle ↄ⃝. It has no legal meaning.
- The registered trademark symbol is the symbol ® (the capital letter R enclosed by a circle), and is used in some jurisdictions to designate a trademark that has been registered in an official office of record (such as the U.S. Patent and Trademark Office in the United States).
- The non-obligatory symbol used in a mask work protection notice is Ⓜ (capital letter M enclosed in a circle.)
- In Japan, Ⓧ is used too.
See also 
- 17 U.S.C. § 401
- Universal Copyright Convention, Article III, §1. (Paris text, July 24, 1971.)
- Copyright Act of 1909, §18.
- Copyright Act of 1870, §97.
- 1874 Amendment to the Copyright Act of 1870, §1.
- Arguments before the Committees on Patents of the Senate and House of Representatives, conjointly, on the bills S. 6330 and H.R. 19853, to amend and consolidate the acts respecting copyright. June 6–9, 1906. Government Printing Office. 1906. p. 68.
- "Proposed Copyright Legislation". The Writer. XVIII (6): 87. June 1906.
- Public Law 743—August 31, 1954. 68 Stat. 102.
- Mann, Alastair J.; Kretschmer, Martin, Bently, Lionel (2010). "A Mongrel of Early Modern Copyright". In Deazley, Ronan. Privilege and property: essays on the history of copyright. Open Book Publishers. ISBN 978-1-906924-18-8.
- Molotsky, Irvin (October 21, 1988). "Senate Approves Joining Copyright Convention". The New York Times. Retrieved September 22, 2011.
- 17 U.S.C. § 401(b)
- Stephen Fishman (2010), "The Copyright Symbol", The Public Domain, p. 356, ISBN 978-1-4133-1205-8
- "Unicode copyleft inquiry".
- Hall, G. Brent (2008). Open Source Approaches in Spatial Data Handling. Springer. p. 29. ISBN 3-540-74830-X. Additional ISBN 978-3-540-74830-4. See Open Source Approaches in Spatial Data Handling at Google Books, page 29.