Some leagues use a black flag with a white saltire. This is displayed with a car number if a driver ignores the other black flags for an extended period and also it indicates that that car is no longer being scored. In both NASCAR and IndyCar, the car is not scored again until it pays attention to the black flag by pitting once this flag is displayed.

Ignoring the black flag or the black-white cross flag intentionally may result in post-race disciplinary action in addition to disqualification from the race. Fines, probation, suspensions, and other penalties (e.g., points being docked from championship standings) may result, depending upon the severity of the situation. Wikipedia