Latin fonts basically cover a single system called the Latin alphabet. However, Japanese fonts include characters with different structures, such as kanji, kana, alphanumerical characters, etc. The mechanism to process such multiple character classes is called a “font dictionary.”

Common Japanese OpenType fonts in CFF format include dictionaries for “Kanji,” “Kana,” “Proportional Latin,” “Full-width Latin,” and “Half-width Latin.” Different settings can be applied for each dictionary, such as BlueValues, etc., previously introduced in this series.

The Latin alphabet is designed based on a “line alignment” system, but kanji and kana are placed based on a square frame called a “imaginary body,” so the concept of suppressing overshoot to align with a specific line is not a familiar process. Therefore, in dictionaries for kanji and kana, dummy values, which are practically non-functional, are set for BlueValues.

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