Now the “war on women” is being waged in America’s public schools.

A parent posted a picture to Imgur of a letter they say is from their local school, notifying them that their daughter’s lunchbox is in violation of the school dress code.

“We noticed that Laura has a Wonder Woman lunchbox that features a super hero image. In keeping with the dress code of the school, we must ask that she not bring this to school,” the letter opens.

“The dress code we have established requests that the children not bring violent images into the building in any fashion — on their clothing (including shoes and socks), backpacks and lunchboxes. We have defined ‘violent characters’ as those who solve problems using violence. Super heroes certainly fall into that category.”

The parents, identified as “Daniel and Sarah” in the letter, obscured the school information and signatory with a napkin and declined to make that public.

They also posted a photo of the offending lunchbox:

The comic book fan site Mary Sue criticized the school’s ban, noting, “Anyone who’s ever actually picked up a comic book knows that most superheroes, 1) turn to violence as a last resort, and usually in self-defense, or when the lives of others are in danger, 2) don’t want to kill anyone, and 3) often have other skills that make them so ‘super’ and are worth looking up to.”

The site wrote, “[Superheroes] often have other skills that make them so ‘super’ and are worth looking up to (Batman’s power of deduction, Superman’s belief in humanity, Wonder Woman’s love of peace).”