eszet

The eszett, also known as the sharp S or "eszett" (German: [ɛsˈtsɛt]), is a German orthographic ligatures. It is composed of a long s (ſ) followed by a z. Historically, it was used as a shorthand for the "ss" digraph, particularly in Gothic and Fraktur typefaces. The eszett represents the voiceless alveolar fricative sound /s/, the same as the regular "ss" digraph or a single "s" at the beginning of a word.

Its usage is primarily in German and some other Germanic languages that have historically borrowed from German orthography. In German, it is used when a long vowel is followed by an unvoiced /s/ sound. For example, in the word "Fuß" (foot), the eszett indicates a long "u" sound followed by an /s/. If the vowel is short, "ss" is used, as in "Kuss" (kiss).

There have been various orthographic reforms concerning the eszett. The current German spelling reform dictates that an eszett is used if the preceding vowel is long or a diphthong, and "ss" is used if the preceding vowel is short. If the eszett is unavailable, "ss" is typically used as a substitute. The lowercase eszett has a distinctive character, while the uppercase form has been a subject of debate and is sometimes represented as "SS".