Latin Capital Letter U with Horn and Acute

Latin Capital Letter U with Horn and Acute at U+1EE8 is an uppercase Vietnamese vowel letter representing Ư with the acute tone mark. It is encoded in the Latin Extended Additional block as a precomposed Latin capital letter for Vietnamese text, where the horn identifies the vowel quality and the acute marks a rising tone. In Vietnamese orthography, this letter is the capital form of ứ and appears when a word beginning with that vowel is capitalized, in all-caps headings, names, signage, and educational materials. The base vowel ư represents a close central unrounded vowel, distinct from ordinary u, while the acute accent gives the sắc tone; for example, it occurs in capitalized forms of words such as Ứng. It is mainly encountered in Vietnamese publishing, government forms, dictionaries, language-learning resources, and personal or place names that must preserve tone marks. A practical distinction is that it should not be replaced by plain U, Ú, or Ư, because each changes either the vowel or the tone and can alter pronunciation and meaning.