There are two major international multilateral copyright conventions which operate in the global system. One is the Berne Convention for the Protection of Literary and Artistic Works (Berne) and the Universal Copyright Convention. Most European and Commonwealth countries belong to Berne, however up to recently the US only belonged to the Universal Copyright Convention. In 1989 the US acceded to the Berne Convention.
Under the Universal Copyright Convention, generally speaking, a work by a national or domiciliary of a country that is a member of the Universal Copyright Convention or a work first published in a Universal Copyright Convention country may claim protection under the Convention. If the work bears the notice of copyright in the form and position specified by the Universal Copyright Convention, this notice will satisfy and substitute for any other formalities a Universal Copyright Convention member country would otherwise impose as a condition of copyright. A Universal Copyright Convention notice should consist of the symbol accompanied by the name of the copyright proprietor and the year of first publication of the work. To qualify for copyright protection in countries that are only members of the Universal Copyright Convention, it is necessary that works bear, in a prominent place and from the time of first publication, the copyright symbol - © - together with the name of the owner of the copyright and the year of first publication, for example: © Kaltons Internet and Technology Solicitors 2002.
However, under the Berne Convention, generally, a work first published in a Berne Union is eligible for protection in all Berne member countries. There are no special requirements like affixing the copyright symbol.
Use of the copyright symbol was significant when the US was not a member of the Berne Convention and it would only recognise copyright where the © symbol was used in accordance with the UCC. The UCC has been largely overtaken by the other treaties that do not require any formalities.
However, using the © symbol, while having little legal effect, alerts others that copyright is claimed in the material in question, and removes any argument that the user relied on an implied licence to use the work.