Progressive encroachment

U.S. trademark law
Progressive encroachment is a doctrine that states that a trademark owner has no obligation to bring suit against an infringer until the likelihood of confusion "looms large." Under the doctrine, a delay in bringing suit for trademark infringement is to be measured from the time at which the plaintiff knows or should have known that it had a provable claim. Laches will be excused if the defendant changes its business significantly so that the likelihood of confusion is significantly greater.