>>286,312
CJK互換文字のラウンドトリップ用のものはUnicode規格書に明記されてる

> They are included in the Unicode Standard to provide full round-trip compatibility
> with the ideographic repertoire of ... and should not be used for any other purpose.
http://www.unicode.org/versions/Unicode10.0.0/ch18.pdf#page=21