It's 7.9.17 in the rulebook:
“Any participant who, in the opinion of the officials, positions a car, equipment, and/or personnel so as to create a hazard or disruption to the event or to interfere with the activities of another competitor may be penalized."
Obviously, it's in reaction to what happened in last week's race at Sonoma Raceway when race leader Scott Dixon was issued a drive-through penalty for hitting the pit equipment of Will Power's crew. Two crew members were knocked to the ground, and Power went on to win the race.
There were many in the sport who feel Power's outside tire changer encouraged Dixon to hit the tire. Team Penske has not allowed the crew member, Travis Law, to be interviewed.
IndyCar also added point-of-reference zones to the outside edge of each pit box to aid in monitoring pit stop conduct and etiquette in this weekend's Grand Prix of Baltimore.
IndyCar also amended its rule regarding display of the blue flag, which calls for a driver to give consideration to an approaching car attempting to overtake. Failing to yield within one lap will draw a penalty, the rule says. Autoweek