The nominative fair use doctrine comes into play when one company uses the mark of another company (usually a competitor) to refer to the mark holder’s product. While most people in marketing know about the nominative fair use doctrine, lawyers are hard-pressed to provide a clear definition. Different courts have developed different tests and applications of the doctrine. Most courts do recognize that “no unnecessary use” is permitted, rather, the minimal use necessary to make the reference to the competitor’s brand is all that is permitted to fall within the scope of “nominative” use. Emphasizing the competitor’s mark is probably not going to be permitted (by any court). How to assess “nominative” use and the “likelihood of confusion” will be both fact and geography dependent until a higher court makes law on these important issues.
It is a best practice to check with your in-house counsel or outside trademark attorney when you use a competitor’s mark in advertising. Catching any problems or risks before liability is imposed will minimize your legal budget for putting out fires.