I am male so this might be different for women.
I wore jeans and either a polo or a button down shirt. I wore a T-Shirt the last day but that is because I didn't want to change before my flight. However I felt a bit under-dressed (especially in the T-Shirt), not in the context of the other people at the convention, but when I went to talk one on one with some of the speakers (especially the lawyers).
Convention staff wears an AAPC polo with slacks.
You know thinking about it, this post may be a bit too late now lol