Millinery justice

So what’s the deal with women getting to wear hats indoors? Can they wear any kind of hat? Hard hat? Top hat? Or does it have to be something decorative, as might be designed by a milliner? I guess the rule, if you can call it a rule, is that a woman is free to wear a fried egg on her head, call it a hat, and proceed in that manner to the restaurant or the concert or the dance. But don’t get me wrong. It’s not that I want to wear hats indoors. Rather, I’d like to have the option of doing so. It’s only fair.