I just wanted to mention a few things. I know sexism in the workplace is a really bad thing, but I think for things like this, education is more important than a lawsuit. I think my boss had good intentions, but he was clueless about working with women and calling him “daddy”, which wouldn’t have been offensive if his own “girlie” daughter called him that made sense to him. Even though he didn’t have bad intent, his calling my coworker “Mike” and me “girlie” was demeaning.
I don’t actually mind the term “girl” for women in a casual setting. I call myself girl sometimes. Usually I prefer “guy” for myself, but that’s just a thing about me. But a workplace is different. If everyone in the office is getting called by name, and you are “girlie” that’s a bad sign. It means you are not getting the basic respect allotted to everyone else. If everyone else in the office was “dude” instead of their first name, it wouldn’t have bothered me.
My mom once made a point to one of her coworkers. He told her not to go into the coffee lounge because everyone was making sexist jokes and she’d get offended. She asked him how he’d feel if my mom told him not to go into the lounge because everyone was telling really racist jokes and because he was black, he might get offended. He blanched and made a really sick face. But that hit home to him and he worked at cleaning up the lounge.
I think intent is important, but I think that in some places you should let things slide (total stranger who would have called you asshole instead of girl if you were a guy, for instance) but in other cases, you should speak up. Even if you have a sense of humor about it—if everyone else has a name, but you’re referred to by a word that describes your demographic, you need to fix it.