Copyright is a form of protection provided by US law to authors of "original works of authorship". When a work is published under the authority of the copyright owner, a notice of copyright may be placed on all publicly distributed copies or phonorecords. The use of the notice is the responsibility of the copyright owner and does not require permission from, or registration with, the Copyright Office.

Use of the notice informs the public that a work is protected by copyright, identifies the copyright owner, and shows the year of first publication. Furthermore, in the event that a work is infringed, if the work carries a proper notice, the court will not give any weight to a defendant's use of an innocent infringement defense—that is, to a claim that the defendant did not realize that the work was protected. An innocent infringement defense can result in a reduction in damages that the copyright owner would otherwise receive.

US law no longer requires the use of a copyright notice, although placing it on a work does confer certain benefits to the copyright holder. Prior law did, however, require a notice, and the use of a notice is still relevant to the copyright status of older works.

For works first published on or after March 1, 1989, use of the copyright notice is optional. Before March 1, 1989, the use of the notice was mandatory on all published works. Omitting the notice on any work first published from January 1, 1978, to February 28, 1989, could have resulted in the loss of copyright protection if corrective steps were not taken within a certain amount of time. Works published before January 1, 1978, are governed by the 1909 Copyright Act. Under that law, if a work was published under the copyright owner's authority without a proper notice of copyright, all copyright protection for that work was permanently lost in the United States.

Section 401 of the Copyright Act specifies the form and location of the copyright notice. The form used for "visually perceptible" copies—that is, copies that can be seen or read, either directly (such as books) or with the aid of a machine (such as films)—differs from the form used for phonorecords of sound recordings (such as compact discs or cassettes).

The notice for visually perceptible copies should contain all three elements described below. They should appear together or in close proximity on the copies.

• The symbol © (letter C in a circle); the word “Copyright”; or the abbreviation “Copr.”

• The year of first publication. If the work is a derivative work or a compilation incorporating previously published material, the year date of first publication of the derivative work or compilation is sufficient. Examples of derivative works are translations or dramatizations; an example of a compilation is an anthology. The year may be omitted when a pictorial, graphic, or sculptural work, with accompanying textual matter, if any, is reproduced in or on greeting cards, postcards, stationery, jewelry, dolls, toys, or useful articles.

• The name of the copyright owner, an abbreviation by which the name can be recognized, or a generally known alternative designation of owner.

Example: © 2012 Jane Doe

The “C in a circle” notice is used only on “visually perceptible” copies. Certain kinds of works, such as musical, dramatic, and literary works, may be fixed not in “copies” but by means of sound in an audiorecording. Since audiorecordings such as audiotapes and phonograph discs are “phonorecords” and not “copies,” the “C in a circle” notice is not used to indicate protection of the underlying musical, dramatic, or literary work that is recorded.