In
typesetting, the
hook or
tail is a
diacritic mark attached to letters in many alphabets. In shape it looks like a hook and it can be attached below as a
descender, on top as an
ascender and sometimes to the side. The orientation of the hook can change its meaning: when it is below and curls to the left it can be interpreted as a
palatal hook, and when it curls to the right is called hook tail or tail and can be interpreted as a
retroflex hook. It should not be mistaken with the
hook above, a diacritical mark used in Vietnamese, or the
rhotic hook, used in the
International Phonetic Alphabet.