Does the "S" stand for "straight"?
If so, why isn't it closer to 100%?
I am pretty sure the S goes with the 2, and it means “two spirit”. I remember coming across that in reading (probably on FR), but have no idea what it means and am not really inclined to find out.
Nope. The "2S" stands for "Two-Spirit," i.e., "Indigenous people who express their gender or sexual identities as different from others."
You could never even make this crap up.