Question: what are half-width alphanumeric characters?
Answer: From Wikipedia, the free encyclopedia. Half-width kana (半角カナ, Hankaku kana) are katakana characters displayed at half their normal width (a 1:2 aspect ratio), instead of the usual square (1:1) aspect ratio. For example, the usual (full-width) form of the katakana ka is カ while the half-width form is ｶ.