Ogonek
The ogonek, also informally referred to as the tail, is a diacritic hook placed under the lower right corner of a vowel grapheme in the Latin alphabets of Polish, Kashubian, Övdalian, and Lithuanian; and directly under a vowel in several Native American languages. An ogonek can also be attached to the bottom of a vowel in Old Norse or Old Icelandic to show length or vowel affection.