I was also going to mention this: cake flour for it's low protein levels. In determining what you're cooking/baking, the brand matters far less than the actual type of flour.

Cake / 'biscuits' (my idea of a biscuit is a solid thing to dip in tea, how British of me, but anyway) flour: about 8-9g of protein per 100 grams of flour.

All-purpose flour: 11-12 grams of protein per 100 grams of flour.

Bread flour: 13-14 grams of protein per 100 grams of flour.

'Pastas' vary a lot. Italian-style uses high-protein durum wheat, which is about 14g/100g. On the opposite end, Chinese jiaozi (steamed/boiled dumplings) use low-protein content (8-9g/100g) to give a very smooth texture.

I'm curious if flour in the US is sold with such nutritional labeling: protein, carbohydrate, fat, salt, etc, measurements per standardised measure (in the EU and much of the world, this is per 100g)?

Yes. See Southern Kitchen.[1]. What matters is the protein content.

- White Lily flour - 9% protein.

- Hard wheat flour - 12% protein

- Cake flour - 6% protein

An equal mixture of cake flour and hard wheat flour is apparently good for biscuits.

Wal-Mart sells the stuff for $0.51/lb, but they're out of stock right now.

[1] https://www.southernkitchen.com/articles/eat/why-southerners...

Indeed: here's a recipe and discussion of protein levels from 11 years ago that talks about White Lily and how to substitute a mix of cake flour and bread flour (and what amounts of baking powder and soda to add to become "self-rising")

http://pinchmysalt.com/how-to-make-the-best-buttermilk-biscu...

There's also pastry flour, which is in between cake flour and AP flour in terms of protein content.