 Katakana was added to the Unicode Standard in October, 1991 with the release of version 1.0.The Unicode block for (full-width) katakana is U+30A0–U+30FF.Encoded in this block along with the katakana are the "nakaguro" word-separation middle dot, the "chōon" vowel extender, the katakana iteration marks, and a ligature of コト sometimes used in vertical writing.