What Is "I18n"? "I18n" is an abbreviation for the word "internationalization". The term "i18n" is derived from its spelling as the letter "i" plus 18 letters plus the letter "n". I+n1t2e3r4n5a6t7i8o9n10a11l12i13z14a15t16i17o18+n Technically, the term is not an acronym, as acronyms represent expressions that are derived from the first letters of words. (For example, "DBCS" is an acronym for "Double