[6] 箱は、CSS 箱モデルにおけるレンダリングの単位要素です。
[8] Editorial: link the term "CSS box" and remove parentheticals (zcorpan著, ) https://github.com/whatwg/html/commit/9058fe7ff6961a28fb6e87db55c7dfbbcbd63bb1
[9] Editorial: link the term "CSS box" and remove parentheticals by zcorpan · Pull Request #4659 · whatwg/html () https://github.com/whatwg/html/pull/4659
[10] Factor out "when it generates a box" · Issue #4618 · whatwg/html () https://github.com/whatwg/html/issues/4618