[tjpnz]

Doesn't seem like a widely used convention.

[waihtis]

That would be because I typed the url wrong, it's actually /.well-known/security.txt:

https://www.facebook.com/.well-known/security.txt

https://www.apple.com/.well-known/security.txt

https://www.amazon.com/.well-known/security.txt

https://www.google.com/.well-known/security.txt