The United States Army's new hair and appearance guidelines have been described as "racially biased" against women who sport dreadlocks or twists.
Thousands have signed a petition requesting that the military amend the regulations in AR 670-1, TIME reported on Monday.
According to the new code, certain hairstyles including "twists, both flat twists as well as two strand twists; as well as dreadlocks, which are defined as 'any matted or locked coils or ropes of hair,'" have been prohibited.
Petition writer Sgt. Jasmine Jacobs, who recently spoke to the Army Times, said she now is "kind of at a loss...with what to do with my hair."
Jacobs said she usually wears her hair in two low-profile twists.
"Most black women, their hair doesn't grow straight down, it grows out," she told the Times. "I'm disappointed to see the Army, rather than inform themselves on how black people wear their hair, they've white-washed it all."
According to a spokesperson at the Pentagon who spoke to TIME, the new rules are an effort to preserve consistency in the armed forces' looks.
"The requirement for hair grooming standards is necessary to maintain uniformity within a military population," the spokesperson said. "Many hairstyles are acceptable, as long as they are neat and conservative. In addition, headgear is expected to fit snugly and comfortably, without bulging or distortion from the intended shape of the headgear and without excessive gaps. Unfortunately, some hairstyles do not meet this standard or others listed in AR 670-1."
The guideline change comes three months after military officials first announced that soldiers would be allowed to don religious wears, grow beards and have tattoos.
Lt. Commander Nate Christensen told the BBC at the time that Muslim, Sikh, Wiccan and Jewish soldiers, sailors, airmen and marines could submit official requests to be exempt from the military's grooming and uniform policies.
Requests were reportedly to be handled on a case-by-case basis, to ensure the exemptions wouldn't hinder "mission accomplishment, unit cohesion, and good order and discipline."