Q: Is it improper for women to wear a hat indoors? (i.e. casual Friday in a business atmosphere?)
A: It depends on the hat. Neither women nor men should wear baseball caps or fishing hats or other outerwear hats indoors. If she is coordinating a hat as a fashion accessory to her ensemble she might wear it, but it is uncommon for a woman to wear a hat in an office. Whether outwear or fashion accessory, hats generally are removed in the workplace.