generated at
X-Frame-Options
https://www.templarbit.com/blog/jp/2018/07/24/top-http-security-headers-and-how-to-deploy-them/#:~:text=方はこちら。-,X-Frame-Options,-HTTPのX
https://developer.mozilla.org/ja/docs/Web/HTTP/Headers/X-Frame-Options
https://nulab.com/ja/blog/typetalk/measure-clickjacking/

Clickjackingなどの対策になる