The spelling espresso is widely considered correct while expresso appears as a less common variant.[15] Italy uses the term espresso, substituting most x letters in Latin root words with s; x is not considered part of the standard Italian alphabet. Italian people commonly refer to it simply as caffè (coffee), espresso being the ordinary coffee to order; in Spain, while café expreso is seen as the more "formal" denomination, café solo (alone, without milk) is the usual way to ask for it when at an espresso bar.