Sino-Korean vocabulary or "Hanja-eo"

The iteration mark 々, which indicates that the previous kanji ought to be repeated.

Alternative spelling of 漢字返し

(orthography, historical) tōyō kanji (kanji that were declared official by the Ministry of Education of Japan on November 16, 1946, later replaced by 常用漢字 (jōyō kanji))

kanji approved for use in names registered in the 戸籍(こせき) (koseki, “family register”)

kanji not approved for regular use

Kanji characters outside of the jōyō kanji and jinmeiyō kanji lists. For example, 攪.