Since I've been watching a lot of baking videos made in the UK (Bakeoff, Mary Berry's solo shows found on YouTube, Cupcake Jemma) I see them using self-rising flour. While I used a mix of AP flour, baking powder, and baking soda (triple sifted) as a substitute, I'm not sure it has the same type of wheat / protein content / milling as British flour. I hear that Southern-style self-raising flour (such as White Lily) is made from a softer wheat - their web site says 100% soft red winter wheat. So it seems like that would be somewhere between a cake flour and all purpose. But again, is that equivalent to the flour available in the UK? I'm in the US South (Florida), so I'll have to look in the bigger supermarkets to see if they have White Lily. One more container of flour in the cabinet! (I hope it's a smaller bag.)
PattyCakes, I think a lot of people refer to "wheat flour" in two different ways - one when they mean whole wheat flour, the brown flour milled with the bran, germ, and all. The other use is to distinguish all flours derived from wheat from the non-wheat substitutes commonly available now for those with either wheat aversions or allergies.Gluten-free/what-free has become very popular in the USA, especially in cities. Alternative flours would include finely milled corn, rice, chickpeas/garbanzos, chia seeds, buckwheat (not an actual wheat as it turns out), oat, coconut, and any of the finely ground nuts like almonds which can sometimes be substituted for flours. I understand that also flour substitutes are used in extremely low-carbohydrate diets (Paleo, Atkins, etc.) mostly for coating and thickening, as they don't really eat breads and cakes.