According to the case-law, the concept of an unfair advantage taken of the distinctive character or the repute of the earlier mark by the use without due cause of the mark applied for encompasses instances where there is clear exploitation and ‘free-riding on the coat-tails’ of a famous mark or an attempt to trade upon its reputation. (Curia Europa)
Thirdly, the Board of Appeal did not base its findings on any evidence to show that there was a real risk, and not merely a hypothetical one, of injury to the reputation of the earlier mark. In particular, it is not apparent from any item of evidence that the applicant sought to ride on the coat-tails of the earlier mark or the message of elegance which it conveys (Curia Europa)
on someone's coat-tails: Gracias a la popularidad o el éxito de otra persona || (US) ayudado por la asociación con otra persona
coat-tail: Las colas largas y afiladas en la parte posterior del frac de un hombre.