Having large breasts.
TL;DR: I was a short girl with tig ol' biddies (38F) at 5'0 tall which is just too much of a fucking contrast for peoples eyes and minds to handle. Worked in customer service. Was told to wear a white shirt with a collar, chose a polo. They told me it was unprofessional, they made official changes to the rules to make me wear button-ups. Button-ups were then deemed "innapropriate" and too "revealing" because of the large gaps between the buttons. They then changed the rules again to force us to wear cardigans. Then made me use my name tag to awkwardly pin my cardigan to my shoulder so that it covered my chest. It was an open-secret that they only changed and enforced these rules for and on me because of how large my breasts are. Because how dare I have breasts.
Also, my current job doesn't shame/harrass me when my buttons on my shirt come undone. So, it's possible to just let a woman be, damnit.
I worked at a customer service desk at the mall. We had a fairly strict dress code in that it dictated we wear only white collar shirts, black slacks, or black, knee-length skirts and flat, black dress shoes.
So, I chose to go with a polo shirt, because button-ups often end up having huge gaps between the buttons which reveal what's behind the shirt, or the shirt can unbutton all together. I even made sure to ask during the interview process that wearing a polo would be acceptable to the code. I was told that polo's were in fact acceptable, so long as they didn't have a logo on them. But a few weeks in they decided it didn't look professional. They demanded I start wearing button-ups. When I refused, I explained why I prefered polo's. I had a large cup size- buttons and large cups don not play nice. The shirt will either have large open gaps between the buttons, revealing what's beneath, or one wrong move makes the buttons come un-done. And it's not even to simply wear a tanktop or camisole underneath, as it's still often deemed innapropriate, and can feel embarrassing when a mishap occurs. Nor is it possible to change the size of the shirt. A smaller size will only compound the problem, and a larger one will be baggy and look unprofessional. I also refused because they had no rule against polo's. They then made official changes to the dress code, saying that we had to wear white button-up business casual dress shirts.
So, of course I go out and get some new shirts as well as some nude tanktops to wear underneath them. Not even a full day into wearing the new shirt I start getting comments about how innapropriate it is for me to dress so "provocatively." I had explained before they imposed the new rule on us that this would happen. And again now, and that short of safety-pinning my shirt together- also out of the question,- I had no control of this.
They then imposed another "official" rule. All women had to wear cardigans. But they never enforced it for anyonr else. Only me. And not only did they refrain from fully enforcing this official rule, but I had to use my name tag to awkwardly pin my cardigan against my shoulder to cover the gaps between the buttons of my shirt.
Meanwhile everyone else is allowed to continue choosing whether or not to wear their cardigans, and moreover, how to wear their cardigans. It was an open secret the the reason the rules were changed were because they didn't like the way a polo looked on me- too innapropriate, too revealing, too provative, I must be an exhibitionist- and that they continued to change them for the same reasons. It was entirely because I had the largest bust-size of the three of us.
That job ended up being one of the worst one's I've had. We could have sued them for that and more. But it's honestly enough for me to know that they couldn't keep anyone on after I left and that they tanked so hard they went out of business.
My coworkers who were pretty cool, nonhate for them, had second jobs, so they weren't left hanging.
That mall still has no customer service personel to this day because the mall management is probelmatic as well. It's honestly amazing that they've been able to keep it running this long.
I now work in a different but also shitty job where I have to to wear a button up shirt. I wear a tanktop or long-sleeved shirt underneath. It has, on multiple occasions, unbuttoned. Sometimes I've noticed right away, other times someone has pointed it out to me. Not once has anyone done so with any judgement in their body language or tone of voice. I've also not had anyone tell me I need to change my uniform, by size or any other degree, for any reason. So, you know, it's possible to just let a woman be, damnit.