The fact is that “woman” is a rich cultural artifact with many cues used to designate that aspect of their identity — I accept the reality of girls’ names, women’s styles, women’s manner of speaking, women’s traditional roles, women’s typical careers, women’s make-up — all the signals that people use to mark their gender. I don’t freak out when a girl is named “Mike”, when a woman is a fighter pilot, when a man uses eye shadow, when anyone uses vocal fry, when a woman interrupts a man. We’re seeing people break out of the stereotypes we impose on men and women in many ways, and I think that’s a great step forward. Let’s treat people as individuals rather than representatives of only two allowed gender classes.

The presence or absence of a penis is possibly the worst gender signal ever, because we keep those hidden in almost all of our social interactions. I’d have to be really close, very intimate friends with a woman before she’d show me her penis.

PZ Myers on signifiers.

Mild content warning at the link, as the above is in response to the presence/bullshit ideas of TERFs.