explanatory phrase rule
explanatory-phrase rule. Trademarks. The principle 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 being that the junior user must include on signs, labels, and advertisements an explanation that the company is not affiliated with the senior user’s company. • The 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.