漢字文化圈
Ruby characters or rubi characters () are small, annotative glosses that are usually placed above or to the right of logographic characters of languages in the East Asian cultural sphere, such as Chinese "hanzi", Japanese "kanji", and Korean "hanja", to show the logographs' pronunciation; these were formerly also used for Vietnamese "hán tự" and "chữ nôm", and may still occasionally be seen in that context when reading archaic texts. Typically called just ruby or rubi, such annotations are most commonly used as pronunciation guides for characters that are likely to be unfamiliar to the reader.