What is another word for "cipher"?

Roget's Thesaurus (1911) lists these synonyms for "cipher": abecedarian, abecedary, absence, affix, alphabet, alphabetical, anagram, anagrammatism, any, character, christcross-row, consonant, dental, digraph, diphthong, dissyllable, drop, egg, goose, guttural, hair, hide, hieroglyphic, hint, ideogram, ideograph, iota, jot, labial, letter, liquid, literal, majuscule, metagrammatism, minuscule, monogram, monosyllable, mute, naught, neither.