History of the word "Ampersand" [...] In the Promptorium Parvulorum (“Storeroom for Young Scholars”), [...] When a single letter formed a word (like I) or a syllable (like the first i- in iris), it was spelled I per se, I or in other words I by itself, I. The per se spellings were used especially for the letters that were themselves words. Because the alphabet was augmented by the sign &, which followed z, there were four of these: A per se, A; I per se, I; O per se, O; and & per se, and. [...] A became a figurative expression for a most excellent or distinguished person or thing. [...] And per se, and was not liable to such figurative use, but it did become, in slightly altered and contracted form, the standard name for the character &.