The traditional test as to whether a later trademark infringes the rights in an earlier trademark is the question of whether a likelihood of confusion will result from the use of the later mark. That issue of a likelihood of confusion takes a number of factors into account.
Important among those factors are the particular trademarks in question and the products or services on which the marks are used, but, depending on the circumstances, other factors come into play such as the marketing channels in which the products are distributed and the target customer base. The issue of infringement is not necessarily a simple one, and it is not limited to a comparison of identical marks on identical products or services.
A more recently recognized form of trademark violation is that of dilution. If a trademark is classified as a “famous” mark, then it can be used to prevent others from using similar marks on noncompetitive products or services that “dilute” the trademark significance of
the mark. This is a developing area of the trademark law. While in many cases, particularly when consumer goods are involved, everyone would generally agree whether a trademark is famous or not, this may not always be the case.
Both with a traditional trademark infringement action or one involving dilution, enforcement is by way of a civil action brought in either federal or state court. It is also possible to bring an action before the International Trade Commission to stop infringing imports.