DECLO, Idaho – The American Civil Liberties Union is threatening to sue an Idaho school district that requires males to wear slacks and a tie and females to wear a dress to high school graduation.

The graduation dress code at Declo High School asks girls to wear a “white or pastel dress or white or pastel blouse and skirt” for its graduation ceremony, while permitting sandals for girls only, reports.

MORE NEWS: Know These Before Moving From Cyprus To The UK

ACLU legal director Richard Eppink sent a letter to Idaho school district superintendents yesterday condemning dress codes for different sexes, and announced the organization has “opened investigations into several school districts in Idaho with apparently discriminatory dress standards.”

Eppink wrote that graduation dress codes like the one at Declo “are the kinds of things that you look at and just shake your head.”

“Cassia County School District, for instance, is a district that’s been trying to convince us for the entire past school year that its people don’t discriminate, and yet here it is, in black and white,” Eppink wrote, according to “It is 2015 here in Idaho, but sometimes you wouldn’t know it.”

Apparently, the year 2015 means all students should be free to dress in clothing traditionally worn by the opposite gender, because denying such constitutes grievous violations of students’ civil rights as well as the state and U.S. Constitution, according to the Associated Press.

Cassia County School District spokeswoman Debbie Critchfield told Reuters there is no district-wide graduation dress code, and those standards are set by individual high schools. Officials also asked administrators at the district’s five high schools to submit for review any instructions on graduation attire given to students, she said.

“The focus on graduation is not what students are wearing but what they have accomplished,” Critchfield said.

MORE NEWS: How to prepare for face-to-face classes

No Cassia County students have ever been barred from graduation over a dress code violation, she said.

Eppink told the AP the ACLU is considering a lawsuit against the Cassia County School District over the graduation dress code at Declo High School.

Officials at several other Idaho school districts told they do not impose any form of gender specific graduation clothing policy, but several send information home with students about “what dressing up means,” Twin Falls School District superintendent Wiley Dobbs said.

“The kids want to know what’s expected for them, so examples are given,” he said.

The ACLU’s targeting of the Cassia County school’s dress code follows a complaint filed by the civil rights group against the district in October over elections for the student body president. Declo High School officials reportedly barred senior Sierra Norman from running for the position because she did not qualify as a full-time student, but the ACLU alleges the decision was based on religious preferences, reports.

“The Normans say the district’s decision was motivated, in part, because Sierra isn’t Morman; the other candidate for class president is,” according to the news site.

Other school districts in neighboring states have faced the wrath of the ACLU for attempting to control student attire. In Utah, school officials edited yearbook pictures to “raise plunging necklines on female students,” Reuters reports.