Home Box Office v. Showtime
United States Court of Appeals for the Second Circuit
832 F.2d 1311 (1987)
Competing premium cable networks HBO (plaintiff) and Showtime (defendant) clashed over Showtime's ad slogan "SHOWTIME & HBO. It's Not Either/Or Anymore," which Showtime used to encourage consumers to subscribe to both services; some, but not all, of Showtime's advertising using the slogan included disclaimers clarifying the companies were separate. HBO sued for trademark infringement, and the district court enjoined use of the slogan without a disclaimer but allowed it when a disclaimer was included; HBO appealed.
Whether a disclaimer clarifying the source of a product can shield a trademark user from an infringement claim if the disclaimer significantly reduces the likelihood of consumer confusion.