Cornet was hit with the violation after returning to court from a 10-minute "heat rule" break between sets, as temperatures approached 100F (38C) in NY.
As Cornet, 28, was walking back on court, she realized her pink-striped shirt was on backward and took it off to reveal a black sports bra, before quickly putting it back on the right way.
She was about to resume the game, and took it off immediately to put it back on correctly, however, at that time, the match referee applied a warning for misconduct.
The Women's Tennis Association - founded by Billie Jean King in the early '70s - demands women change their shirts off court, in the "most private location".
Manchester United stand by José Mourinho and see cause for hope
Once the club announce his extension then fans can be as happy or excited as they like. "That's me purely speaking as a fan". Manchester United legend Ryan Giggs says that Jose Mourinho remains "the right man" to manage the Premier League giants.
Andy Murray's mother Judy Murray, a tennis coach in her own right, claimed there are double standards at play. After changing into this shirt she was given a code violation for the on-court wardrobe change.
Cornet was in the tournament against Swedish tennis player Johanna Larsson.
A clearly perplexed Cornet challenged Rask on his decision, asking why she was getting a violation. We regret that a code violation was assessed to Ms Cornet yesterday. "Back in the old days, our wrists and our ankles couldn't be shown", she said in an interview with NY magazine's The Cut on Tuesday.
Said another critic on Twitter: "Busted for code violation".
Goodman guessing he's 'mopey' widower in 'Roseanne' spinoff
Within a few hours her show was axed, and later this summer it was announced the series would continue without her. John Goodman slipped what will happen to Roseanne Barr's character on the Roseanne spinoff, The Connors .
U.S. Open officials issued a statement on Wednesday apologizing for the penalty, saying Cornet's attire change was not a code violation.
"We have clarified the policy to ensure this will not happen moving forward".
Because of the super high temperatures at the tournament - going up to 38°C - an extreme heat policy was implemented, offering a ten-minute break for women before the third set, and for men before the fourth.
WTA rules state women are not allowed to change while on the court, according to the Daily Mail. "The men can change shirts on court", she tweeted.
Jemele Hill To Part Ways With ESPN
Hill has been fairly invisible at ESPN since departing earlier this year as co-anchor of the 6 PM hour of ESPN's SportsCenter . Those who agreed with her loved the fact she spoke out about political and social issues using her ESPN platform.
Meanwhile, several male players were forced to retire early from their matches this week due to the scorching heat. They will not be assessed a bathroom break in this circumstance'.