Explanatory-Phrase Rule Law and Legal Definition

Explanatory phrase rule is a principle of trademarks law that a senior user of a family-name trademark is entitled to a judicial remedy for unfair competition if the same family name appears on competing goods or services. The remedy provided is that the junior user is asked to include signs, labels, and advertisements to the effect that the company is not affiliated with the senior user's company. This rule resolves two conflicting principles:

(1) everyone has the right to use a family name in business, and

(2) no one may use a family name in a way that unfairly hurts someone else's business.