The copyright symbol consists of the letter "C" in a circle such as "Â." Copyright symbols are used on books, websites, most packaged goods, including foods and medicines, and more.The U.S. Copyright Office has a publication on Copyright Notice, Circular 3, giving background information about copyright law and how to provide proper copyright notice to the public. On works published before March 1, 1989, using the notice was required by law for protection. Generally, for works published on or after that date, using the symbol became optional and a published work can still have copyright protection without it.However, Circular 3 explains how use of the symbol can be beneficial to the copyright owner.â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 defendantâs use of an innocent infringement defenseâ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.â