Comment by palsecam

I use 418 as a reply to illegitimate bots. It’s fun and it makes filtering logs easier.

Nginx config snippet:

  # Nothing to hack around here, I’m just a teapot:
  location ~* \.(?:php|aspx?|jsp|dll|sql|bak)$ { 
      return 418; 
  }
  error_page 418 /418.html;

Example: https://FreeSolitaire.win/wp-login.php (NB: /wp-login.php is WordPress login URL, and it’s commonly blindly requested by bots searching for weak WordPress installs.)