(Internet slang, especially anime and manga fandom) events or things from the past which one wants to whitewash/erase from history (due to it being embarrassing, poorly received, etc.); dark past

oral history

historicism

Chinese (any language spoken in China) / Chinese (class of languages) / Chinese (Mandarin)

the Chūgoku region (western part of Honshu comprising the prefectures of Okayama, Hiroshima, Yamaguchi, Tottori, and Shimane)

China Standard Time

sinicization

(humanities) sinology

China, as opposed to Japan and other islands / mainland China

China proper