It took a little pressure, but Bishop Shanahan High School is rolling back a short-lived policy that would have required girls to wear tights to school all year.

Officials at the Downingtown school relented late Monday after more than 1,300 people signed an online petition opposing the new dress code, arguing that leg coverings were uncomfortable, sexist, and expensive. In an email to the school community, principal Michael J. McArdle said that "medical issues" raised by parents, along with the general backlash, made him rethink the policy.

On June 22, McArdle notified parents at the Chester County school that tights would be mandatory for their daughters starting in the fall, a change from allowing girls to wear knee socks in warmer months. He offered no explanation.

The note ignited a dress-code battle at the Catholic archdiocesan high school, with parents calling the principal to protest and the online petition calling the rule an attempt to cover up female students' lower legs so they would not be ogled by male classmates and faculty.

Parents and students condemned the policy as sexist and medically hazardous. The petition called it "unfair, uncomfortable, and unjust" for girls to have "to cover our shins because it is distracting to male students and teachers."

The petition, started by rising senior Grace McCafferty, also said that tights — which could be black, green, gray, or white to match green plaid skorts, a skirt with shorts underneath — are more expensive than knee socks, do not last as long, shrink easily, and could earn demerits for the wearer if torn.

Monday morning, the petition had 1,363 signatures.  The school has about 1,300 students.

At nearly all the 18 high schools in the Roman Catholic Archdiocese of Philadelphia, girls' uniforms consist of a jumper or skirt and a blouse, with tights in winter and knee socks in fall and spring, although some allow students to choose their leg wear. Only one other school, Archbishop Prendergast in Drexel Hill, demands that girls always wear tights.

McArdle said the policy had nothing to do with boys' interest in girls' legs.  The administration was looking for "what creates the best impression or best look," he said. "We want our students to be representative of our school and our values, and we considered this as a way to improve that on a year-round basis."

Female students increasingly are confronting public and parochial schools over dress codes that they say reflect a double standard, allowing boys far more sartorial leeway. Rather than forcing girls to dress so boys won't leer, they say, boys should be punished for leering.

"Teach the boys to control themselves — don't make us change for them," Lindsey Ward of West Chester wrote on the petition.

Barbara McClay, a mother of four, including two girls, said she was concerned by the expense, but also by the way the change was handed down without any stated reasons. Girls are often reprimanded when their knee socks fall down and have been told that it is a distraction for boys, she said.

Girls should dress modestly, especially at a Catholic school, McClay said, but "this knee-sock thing seems over-the-top targeted. I don't understand it."

She and others also expressed the concern, widely acknowledged in medical circles, about girls developing yeast and urinary tract infections from wearing leggings and tight jeans, especially in warm months.

At 5 p.m. Monday, McArdle sent  an email saying that "after reviewing concerns raised by parents and students … that tights be worn throughout the school year, the school administration has decided to rescind this uniform requirement change."

For students, that was welcome news. One 16-year-old rising junior said that wearing tights, especially in hot weather, is uncomfortable when added to the skort.

"That's a lot of layers," said the student, who said she did not want to be identified for fear of retribution from school administration.

She said the complaint that girls don't always have their socks pulled up to their knees makes no sense. "Boys don't always wear their shirts tucked in," she said, adding that boys are allowed to wear V-neck sweaters over shirts while girls have to wear crew necks.

She called the school's dress code strict, especially regarding proms, for which girls are given a special presentation with pictures of acceptable and unacceptable dresses — no plunging necklines, no low-cut backs, no high slits.

"They say they don't want boys misbehaving, but it should be on the boys not to misbehave," she said. "And I think the boys at Shanahan are very respectful."