Call it The Landmaid's Tale: two girls were barred from boarding a flight by a United Airlines agent Sunday, and the airline confirmed that leggings are against a dress policy it applies to people traveling on passes issued to employees and their dependents.

A United Airlines gate agent barred two girls from boarding a flight Sunday morning because the girls were wearing leggings.

Another girl who was wearing gray leggings had to change before she was allowed to board the flight from Denver to Minneapolis, a witness said.

“She’s forcing them to change or put dresses on over leggings or they can’t board,” Shannon Watts, who was at a gate at Denver International Airport said on Twitter. “Since when does @united police women’s clothing?”

The airline, when challenged, backed up its gate agent on Twitter.

@shannonrwatts In our Contract of Carriage, Rule 21, we do have the right to refuse transport for passengers who ... https://t.co/52kRVgaCyb

— United (@united) March 26, 2017

"Casual attire is allowed as long as it looks neat and is in good taste for the local environment," tweeted a United Airlines spokesperson.

The "contract" referred to turns out to be very vague indeed, specifying only that passengers must be "properly clothed."

Later, though, United Airlines said that the girls were "United pass travelers" who are "United employees or their eligible dependents standing by on a space-available basis," meaning that the company was was applying an employee policy to someone "who was denied boarding this morning because her attire didn’t meet the United pass travel clothing requirements." Normal passengers' attire "doesn't need to meet the United pass travel clothing requirement," they wrote. Read the rest