Trademark Law in the United States
Trademark law governs the use of a device (including a word, phrase, symbol, product shape, or
logo) by a manufacturer or merchant to identify its goods and to distinguish those goods from
those made or sold by another. Service marks, which are used on services rather than goods,
are also governed by 'Trademark law.' In the United States, certain common law trademark
rights stem merely from the use of a mark. However, to obtain the greatest protection for a
mark, it is almost always advisable to register the mark, either with the federal government,
if possible, or with a state government. A mark which is registered with federal government
should be marked with the ® symbol. Unregistered trademarks should be marked with a
"tm", while unregistered service marks should be marked with a "sm".
A mark is infringed under U.S. trademark law when another person uses a device (a mark) so as
to cause confusion as to the source or sponsorship of the goods or services involved.
Multiple parties may use the same mark only where the goods of the parties are not so similar
as to cause confusion among consumers. Where a mark is protected only under common law
trademark rights, the same marks can be used where there is no geographic overlap in the use
of the marks. Federally registered marks have a nation-wide geographic scope, and hence are
protected throughout the United States.