The Seahawks announced Thursday that undercover cops will patrol CenturyLink field dressed as 49ers fans.
The officers will be tasked with upholding the Seahawks' fan code of conduct, which prohibits foul or abusive language, intoxication and physical harassment.
Fans breaking the code will be kicked out and forced to take an online course if they want to return in the future.
Seattle fans are among loudest in the National Football League, making their home field of the toughest places for opposing teams to play.
