翻訳で作られてる記事だけど原文の英語版Wikipediaの一文
Speculations include that the use of x to indicate a kiss was transferred from earlier symbolic uses of the letter. Allegedly, in the Middle Ages, a Christian cross might be drawn on documents or letters to mean sincerity, faith, and honesty; the sign was certainly sometimes used in place of a signature.[3]
しか訳されてなくて他の4段落分の文章が欠落してるのひどい
