http://en.wikipedia.org/wiki/Trademark





A trademark, trade mark, or trade-mark[1] is a distinctive sign or indicator used by an individual, business organization, or other legal entity to identify for consumers that the products or services on or with which the trademark appears originate from a unique source, designated for a specific market,[2] and to distinguish its products or services from those of other entities.
A trademark may be designated by the following symbols:
  • ™ (the "trademark symbol", which is the letters "TM", for an unregistered trade mark, a mark used to promote or brand goods)
  • ℠ (which is the letters "SM" in superscript, for an unregistered service mark, a mark used to promote or brand services)
  • ® (the letter "R" surrounded by a circle, for a registered trademark)
A trademark is typically a name, word, phrase, logo, symbol, design, image, or a combination of these elements.[3] There is also a range of non-conventional trademarks comprising marks which do not fall into these standard categories, such as those based on color, smell, or sound.
The owner of a trademark may initiate legal proceedings for trademark infringement to prevent unauthorized use of that trademark. Most countries require formal registration of a trademark as a precondition for pursuing this type of action. A few countries, including the United States and Canada, also recognize common law trademark rights, which means action can be taken to protect a trademark that is in use but not registered. Generally, common law trademarks do not offer the holder as much legal protection as registered trademarks.
The term trademark is also used informally to refer to any distinguishing attribute by which an individual is readily identified, such as the well-known characteristics of celebrities. When a trademark is used in relation to services rather than products, it may sometimes be called a service mark, particularly in the United States.[3]

Fundamental concepts
The essential function of a trademark is to exclusively identify the commercial source or origin of products or services, so a trademark, properly called, indicates source or serves as a badge of origin. In other words, trademarks serve to identify a particular business as the source of goods or services. The use of a trademark in this way is known as trademark use. Certain exclusive rights attach to a registered mark, which can be enforced by way of an action for trademark infringement, while unregistered trademark rights may be enforced pursuant to the common law tort of passing off.
It should be noted that trademark rights generally arise out of the use of, or to maintain exclusive rights over, that sign in relation to certain products or services, assuming there are no other trademark objections.
Different goods and services have been classified by the International (Nice) Classification of Goods and Services into 45 Trademark Classes (1 to 34 cover goods, and 35 to 45 services). The idea behind this system is to specify and limit the extension of the intellectual property right by determining which goods or services are covered by the mark, and to unify classification systems around the world.


Symbols
The two symbols associated with U.S. trademarks ™ (the trademark symbol) and ® (the registered trademark symbol) represent the status of a mark and accordingly its level of protection. While ™ can be used with any common law usage of a mark, ® may only be used by the owner of a mark following registration with the relevant national authority, such as the U.S. Patent and Trademark Office (USPTO or PTO). The proper manner to display either symbol is immediately following the mark in superscript style.




Terminology
Terms such as "mark", "brand" and "logo" are sometimes used interchangeably with "trademark". "Trademark", however, also includes any device, brand, label, name, signature, word, letter, numerical, shape of goods, packaging, colour or combination of colours, smell, sound, movement or any combination thereof which is capable of distinguishing goods and services of one business from those of others. It must be capable of graphical representation and must be applied to goods or services for which it is registered.
Specialized types of trademark include certification marks, collective trademarks and defensive trademarks. A trademark which is popularly used to describe a product or service (rather than to distinguish the product or services from those of third parties) is sometimes known as a genericized trademark. If such a mark becomes synonymous with that product or service to the extent that the trademark owner can no longer enforce its proprietary rights, the mark becomes generic.



Wrongful or groundless threats of infringement
Various jurisdictions have laws which are designed to prevent trademark owners from making wrongful threats of trademark infringement action against other parties. These laws are intended to prevent large or powerful

companies

from intimidating or harassing smaller companies.
Where one party makes a threat to sue another for trademark infringement, but does not have a genuine basis or intention to carry out that threat, or does not carry out the threat at all within a certain period, the threat may itself become a basis for legal action.[20] In this situation, the party receiving such a threat may seek from the Court a declaratory judgment; also known as a declaratory ruling.