trademark / service mark
(law) An intangible right granted by law to an individual, business, or other legal entity for a word, name, symbol, or design, or a combination of these elements, used, or intended to be used, to identify and distinguish the goods of one manufacturer or seller from goods manufactured or sold by others, and to indicate the source of the goods.
A service mark is any word, name, symbol, design, or a combination of these elements, used, or intended to be used, to identify and distinguish the services of one provider from the services provided by others, and to indicate the source of the services.
Trademark protection varies from country to country, and may not be available in some jurisdictions. If trademark protection is available under the laws of a particular country, a trademark may usually be registered only if it is distinguishable from other registered trademarks and if it contains a name, brand, label, signature, word, letter, numeral, device, or any combination of these items. A country that is a member the Paris Convention for the Protection of Industrial Property may recognize trademarks held in other jurisdictions.
Trademarks are registered on a country-by-country basis and are subject to different country laws and regulations regarding registration and use. In general, trademarks, unlike patents, can be renewed forever as long as they are being used in commerce.
Trademarks and service marks are designated by the following symbols:
TM (TM in superscript) Used to identify an unregistered trademark. A mark used to promote or brand goods.
SM (SM in superscript) Used to identify an unregistered service mark. A mark used to promote or brand services.
© (R in a circle in superscript) Used to identify a registered trademark. A mark used to promote or brand goods or services.
(U.S.) Organizations that file an application at the U.S. Patent Office and use the brand for five years may be granted a trademark. A firm may lose a trademark that has become generic. Generic names are those which consumers use to identify the product, rather than to specify a particular brand (e.g., escalator, aspirin and nylon).
In the U.S., the national trademark registration agency is the U.S. Patent and Trademark Office, Washington, DC USA, Tel:  (800) 786-9199 (toll-free);  (571) 272-1000, Web: www.uspto.gov.
In the European Union, the trademark registration agency is OHIM, The Trade Marks and Designs Registration Office of the European Union, Alicante, Spain, Tel:  96 513 9100, Web: http://oami.europa.eu/ows/rw/pages/index.en.do.
See Berne Convention, copyright; service mark; patent; World Intellectual Property Organization; Patent Cooperation Treaty.