Any store coupon can be stacked with a manufacturer coupon on 1 item.
You would not stack 2 manufacturer coupons or 2 store coupons on 1 item. (The only exception to this is at Rite Aid where they allow you to use 1 manufacturer coupon, 1 RC49 coupon, and 1 RC48 coupon on 1 item but this is rare to have happen.)
For store coupons, look for the words “store coupon” and a store barcode.
Manufacturer coupons typically list a remit address for Texas where as store coupons will not.