Champion Spark Plug Co. (Champion) (plaintiff) manufactured spark plugs bearing the trademark “Champion.” Sanders (defendant) repaired used spark plugs and resold them. Sanders sold the repaired plugs in a box with “Champion” on it, and the print on the box guaranteed that the spark plugs would be dependable. Sanders did include a note inside the box stating that the plugs had been renewed, but none of the boxes used Sanders’s name. Sanders also included Champion’s own charts indicating the recommended uses of the spark plugs. Champion sued Sanders for infringement of the “Champion” trademark and unfair competition. The district court found that Sanders could not sell any of Champion’s plugs unless any reference to Champion’s trademark was removed, the plugs were clearly labeled repaired, and the boxes clearly indicated that the plugs came from Champion but had been repaired by Sanders. The district court decided not to address the unfair competition claim. The decision was appealed. The appeals court found that Sanders was guilty of trademark infringement and unfair competition. The appeals court modified the district court’s ruling such that Sanders did not have to remove Champion’s trademark but had to clearly label the plugs as used or repaired. Also, the boxes did not need to state that the plugs came form Champion and were repaired by Sanders, but only needed to have a more general statement about the plugs being used or repaired. Champion filed for certiorari. The Supreme Court granted certiorari because of a conflict among appeals courts’ rulings.