"Historical kana usage", a prescriptive method of using kana to write Japanese. Devised in the Edo period by Keichū (契沖) and taught in schools until 1946, it aims to be etymologically faithful and reflects earlier stages of the language (Heian period and earlier).

"Modern kana usage", the method of using kana to write Japanese that has been used after the 1946 (post-war) Japanese national language reform. Unlike its predecessor, it is almost entirely phonetic, reflecting modern language with little ambiguity.

(grammar) pronoun / (figuratively) synonym

stone; rock

sharp

"Special kana usage of ancient times": distinctions in the usage of man'yōgana in early Old Japanese works that were quickly lost.

Alternative spelling of 上代特殊仮名遣

a combat sport match where opponents compete against each other using different styles of martial arts