Of course, dress codes aren’t limited to prom. Year-round there is much wringing over the garments of public-school kids. When we asked our readers about their strangest school dress codes, many wrote that the rules seemed to unfairly target girls—specifically, everything on the female body that lies roughly north of the trachea.

One reader said necklines had to be “no lower than two inches below your collarbones.” Many others described the commandments around tank-top straps:

Dana Owens At a public school in the south -- for girls: no sleeveless tops Laura Anne Galway In the 6th grade I was told I wasn't allowed to wear sleeveless shirts, because my "shoulders would entice the boys." Jyoti Deo No spaghetti straps in, of all places, Florida! Guess shoulders pose a danger somehow. *smh*

Some schools settled on two inches, but others banned sleeveless shirts altogether. Definitely outlawed, in many places, was the wicked “spaghetti” strap. (In my high school, this rule gave rise to an enterprising style choice: A contraband tank-top worn over a white t-shirt. Man, consider yourself stuck to!)

The prom dust-ups made me wonder, was it always thus? Should teens today rage against the cleavage-measuring machine, or should they thank their lucky Snapchats they don’t get busted for wearing “draped fabrics,” like some of their foremothers did?

The answer is a little of both, and it depends on how you view teens’ role in society. Are they mini-adults who should be spared the oft-embarrassing choices made by their underdeveloped prefrontal cortices? Or are they fully autonomous beings, whose clothing decisions are as valid as anyone else’s?

There were always dress codes, especially in schools. But they weren’t always written down—and they weren’t always set by school administrators directly. When they were enforced, however, they have always seemed to affect women disproportionately.

Until the early 20th century, not everyone went to high school. When that began to change, around the 1920s, high-school girls’ clubs would create “dress standards” for the students. But their biggest concern wasn’t naked shoulders or cleavage—it was “dressing in an undemocratic way,” said Linda Przybyszewski, a professor of history at the University of Notre Dame. Students were worried about peers “wearing fancy clothes to school to show off your money.”

As Przybyszewski writes in her book, The Lost Art of Dress, in the early 20th century a prominent group of female fashion writers essentially taught women of all ages how to dress for any occasion.

These women, whom Przybyszewski calls “The Dress Doctors,” wrote hundreds of pamphlets and books that women read in their home-ec classes and 4-H clubs. The Doctors schooled women on what was suitable to wear at different ages, how to be thrifty while still being stylish, and that “fad” stands for “For A Day.” One of their rules was that there are six distinct occasions for dressing: school, business, housework, sport, afternoons, and evenings. Each required specific cuts and fabrics—hence all the “dressing for dinner” we see on Downton Abbey.