The dieresis in Johto Mono is the perfect way to add a touch of retro to your text. The diaeresis (/daɪˈɛərɪsɪs/ dy-AIR-ə-sis; also known as the tréma) and the umlaut are two different homoglyphic diacritical marks that consist of two dots ( ¨ ) placed over a letter, usually a vowel. When that letter is an i or a j, the diacritic replaces the tittle: ï. When the letter is an u, the result is ü. The dieresis is two small dots placed above a letter, usually a vowel.