 A food may be labeled "plus" to describe its nutrients only if it contains at least 10% more of the Reference Daily Intake or Daily Reference Value compared to the usual amount.Because Diet Coke Plus labeling does not indicate the increased amount of nutrients, it cannot use the word "plus" on its label.Regardless, snack foods, such as carbonated soda, may never use the word "plus" because the FDA does not consider it appropriate to fortify snack foods.