The mind is a lint trap--I remember seeing it, now I have to figure out where that was.
Pastry flour and cake flour are about the same, I think. Very finely ground. My mother used to get one called Swans Down or something similar.
I have an immigrant cookbook with old-world recipes that I thought I might have seen it in, but no luck there. It's off to the old Fanny Farmer and the Amish cookbooks next.