Seven students are suing a Texas school district over its dress-code policy banning boys from having long hair.
School officials suspended a 9-year-old boy for a month, barred him from recess and normal lunch breaks as punishment for long hair, the lawsuit claims.
He and the other students, aged 7 to 17, say the policy violates the constitution and Title IX - a federal law prohibiting sex discrimination.
The school district said on Thursday it was reviewing the lawsuit.
Magnolia Independent School District "respects varying viewpoints, and we respect the rights of citizens to advocate for change," spokeswoman Denise Meyers said in an email to US media.
The district, which serves roughly 13,000 students about 40 miles (64km) northwest of Houston, did not return a request for comment from the BBC.
According to its dress code policy, boys cannot wear their hair over their eyes, past the bottom of their ears, or past the bottom of a dress shirt collar. Facing backlash this summer, Magnolia defended the policy, saying it "reflects the values of our community at large".
The suit, filed by the American Civil Liberties Union of Texas (ACLU) on Thursday on behalf of the students, argues the school district "imposed immense and irreparable harm... solely because of these students' gender".
It details a number of punishments given to the students - six boys and one non-binary child - for wearing long hair.
One, a nine-year-old identified as AC, is Latino, and wears his hair long like his father and uncle as a part of his family's heritage, the suit says. Another, an 11-year-old identified as TM, is non-binary and has worn long hair as a "critical component" of their gender expression.
Both have been subjected to punishments including suspension, denial of extracurricular activities and separation from their peers.
"This rule is a complete and utter dinosaur," said parent Stanley Burkhead, whose son has long hair, at a school board meeting in August.
"Who are we to tell him who he can't be? Who are we to tell him what a boy should look like?" he said. A survey by the ACLU of Texas last year found that nearly 500 public school districts in the state have some type of a hair-length policy only for boys.
Credit: The BBC