Section 10 of the Lanham Act contains an anti-trafficking rule which prohibits the assignment of an intent-to-use-based trade mark application except where such assignment is to a successor to the business of the applicant or portion thereof to which the mark pertains. This provision played a key role in a decision recently rendered by the US Court of Appeals for the Federal Circuit in Emerald Cities Collaborative, Inc v Sheri Jean Roese. This ruling serves as an important reminder about the laws prohibiting the assignment of intent-to-use based trade mark applications, the risks in pursuing enforcement efforts when a mark might not have been properly assigned and the importance of asserting common law rights in a notice of opposition.