 Addition of the small "y" kana is called yōon.Small versions of the five vowel kana are sometimes used to represent trailing off sounds (ハァ "haa", ネェ "nee"), but in katakana they are more often used in yōon-like extended digraphs designed to represent phonemes not present in Japanese; examples include チェ ("che") in チェンジ "chenji" ("change"), ファ ("fa") in ファミリー "famirī" ("family") and ウィ ("wi") and ディ ("di") in ウィキペディア "Wikipedia".A character called a "sokuon", which is visually identical to a small "tsu" ッ, indicates that the following consonant is geminated (doubled); this is represented in rōmaji by doubling the consonant that follows the "sokuon".