If hydroxide, or caustic alkalinity, is present the alkalinity to
phenolphthalein is greater than one-half the alkalinity to methyl
orange, erythrosine, or lacmoid; the alkalinity is due entirely to
hydroxide if the phenolphthalein alkalinity is equal to the methyl
orange, erythrosine, or lacmoid alkalinity. If the phenolphthalein
alkalinity is more than half and less than all the methyl orange,
erythrosine, or lacmoid alkalinity, hydroxide, expressed in terms of
calcium carbonate, is equal to twice the phenolphthalein alkalinity
minus the methyl orange, erythrosine, or lacmoid alkalinity.