Fonte: [RFC 3514]
1. Introduction

Firewalls [CBR03], packet filters, intrusion detection systems, and
the like often have difficulty distinguishing between packets that
have malicious intent and those that are merely unusual. The problem
is that making such determinations is hard. To solve this problem,
we define a security flag, known as the “evil” bit, in the IPv4
[RFC791] header. Benign packets have this bit set to 0; those that
are used for an attack will have the bit set to 1.

Leggendo questo documento, mi sono imbattuto nell’indicazione di questa RFC “umoristica”.
Davvero curioso 🙂