The owner of a registered trademark may commence
legal proceedings for trademark infringement to
prevent unauthorised use of that trademark.
However, registration is not required. The owner
of a common law trademark may also file suit,
but an unregistered mark may be protectable only
within the geographical area within which it has
been used or in geographical areas into which it
may be reasonably expected to expand.
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.
It is important to note that trademark rights generally arise out of the use and/or registration (see below) of a mark in connection only with a specific type or range of products or services. Although it may sometimes be possible to take legal action to prevent the use of a mark in relation to products or services outside this range (eg. for passing off), this does not mean that trademark law prevents the use of that mark by the general public. A common word, phrase, or other sign can only be removed from the public domain to the extent that a trademark owner is able to maintain exclusive rights over that sign in relation to certain products or services, assuming there are no other trademark objections.
