This is an old April Fool's joke, but I wanted write the post, so I could easily find it later.
The Security Flag in the IPv4 Header
Request for Comments: 3514
RFC 3514 The Security Flag in the IPv4 Header 1 April 2003
The bit field is laid out as follows:
0
+-+
|E|
+-+
Currently-assigned values are defined as follows:
0x0 If the bit is set to 0, the packet has no evil intent. Hosts,
network elements, etc., SHOULD assume that the packet is
harmless, and SHOULD NOT take any defensive measures. (We note
that this part of the spec is already implemented by many common
desktop operating systems.)
0x1 If the bit is set to 1, the packet has evil intent. Secure
systems SHOULD try to defend themselves against such packets.
Insecure systems MAY chose to crash, be penetrated, etc.