diacritic

diacritic: in Sumerian, a diacritic is a mark or symbol added to a letter to change its meaning. Because each cuneiform sign can be read multiple ways, you’ll often see numbers after the last letter of the word (in subscript), indicating how the sign is supposed to be read—ex.  2 = éš. This technique is used for simplicity in transliteration and has no bearing on pronunciation.