This will give you an idea http://news.ycombinator.com/item?id=591309

Did you really mean sex, or did you mean gender?

Just raising the thought, there's a difference.

I can't say I know that much about the transgender community, but as I understand it:

Sex is the parts you're born with. Gender is your mental identity. People have operations to make their sex match their gender.

It may sound silly at first to some, but if you've ever talked to someone who has a different gender than sex, you'd understand it's a real thing.

That's a pretty good summary.

For what it's worth, here's some transgender terminology worth knowing:

Transgender: a person who identifies as a gender that doesn't match their genitalia at birth (some transgendered folks have genital reassignment surgery, some don't)

Transman: A female-to-male transgendered person (identifies as male)

Transwoman: A male-to-female transgendered person (identifies as female)

Gender queer: some folks who identify somewhere on the gender spectrum outside the male/female binary identify as "gender queer"

Also important to note, gender identity does not define sexual orientation.

apparently people can tell what she means.