ROCKFORD, Ill. – An Illinois school’s 21-page rule book for prom attire is drawing complaints from students and accusations of body shaming from “experts.”

Boylan Catholic High School issued a Prom 2017 Proper Dress and Dance Policy in January to set clear expectations for “modest” attire at this year’s event, and officials held a meeting with senior girls to explain the rationale behind the rules.

But students are balking at the strict rules, in part because they allegedly shame girls with certain body types.

“There is a lot of understandable discontent among the girls over the strict enforcement of the new dress code,” student council president Kaleigh Brauns told the Rockford Register Star.

Boylan’s “dress code guidelines” come with a warning: “Guidelines will be strictly enforced. Students, including guests, not in compliance with Dress Code will not be admitted to the dance and refunds will not be issued. There will NOT be a loaner clothing option.”

“Dresses and attire that reflect modesty are required,” the policy reads.

The rules are simple for gentlemen: “Young men are expected to wear formal evening attire that would include a tuxedo, suit with a tie, or sport coat and slacks with a tie.”

Guidelines for the ladies, however, are a little more complex.

Dress necklines “must be cut in a modest way without showing cleavage” and any cuts in the back or sides “must not be cut below the navel (below your elbow.)”

Dresses must also be no shorter than mid-thigh, and slits “may be no higher than three inches from the knee.”

Girls cannot show their navel or cleavage, or wear “excessively tight” dresses.

According to the policy, which comes complete with pictures to illustrate the rules, “some girls may wear the same dress, but due to body types, one dress may be acceptable while the other is not.”

Robyn Goodman, a body image “expert” at the University of Florida, contends the line about different body types “is discriminatory and supports body shaming.”

“Girls do not have a choice in how their bodes were made so more voluptuous bodies are going to have more cleavage and curves. Taller girls’ dresses will hit higher up on the leg than a shorter girl. It’s nature,” Goodman wrote to the Register Star in an email.

“Telling one girl she has to restrict her body by only wearing certain fashions and telling another her body is fine for any fashion is sending a message about what is the ‘right’ body to have and what is the ‘wrong’ body,” Goodman wrote. “These messages are often damaging to girls. We are not allowed to discriminate in the U.S. based on race, disability, gender, age, etc. … So why are schools discriminating against girls based on their bodies?”

Boylan President Amy Ott acknowledged that students come in different shapes, but said all students are held to the same standard of modesty.

“We’re all different shapes and sizes,” Ott said. “You have to try a dress on and see what it looks like on you, not how it looks on someone else. … It’s like shopping for any other kind of clothing in this day and age. You want to look your best and look appropriate.”

Ott explained that several girls were forced to cover up during the Homecoming dance last fall, and administrators simply wanted to ensure students understood the rules before purchasing a dress for prom.

“We wanted everyone to know the expectations ahead of time,” Ott said. “We think it’s important as a Catholic institution to help our students see that they can be elegant and modest and beautiful at the same time.”

Brauns, the student council president, said some students have discussed ditching the prom because of the rules, but thinks most will eventually get over it.

“We must understand that being part of a Christ-centered community means holding ourselves to a higher discipline in the way we speak, in the way we act and in the way we dress,” she said.