Oh-and in fact, a lot of it is personal preference.
I got RAILED ON this summer for using the term black (vs african american). Unbeknownst to the person who railed on me-who is a visitor to our community-my group of close friends AND family-include MANY blacks who DO NOT appreciate being called African American because they aren't from Africa, nor were their parents, grandparents, great-grandparents etc... There ARE other countries where black people come from besides Africa.
So preference does come into play. Some people prefer black, some people prefer African American.
Some people prefer lady, some woman, some (like me) don't give a shit if someone calls me a chick.
I have a lesbian friend who PREFERS dike and that's pissed off other people too-who insist she shouldn't self-identify that way.
It really comes down to asking individuals what THEY wish and as individuals-letting people know when some label bothers us.
"Love As Thou Wilt"