When the IP standard was defined, was this bit purposely left undefined? Is this newer RFC really a joke, and nothing but a joke? How come the IETF allows just-kidding RFCs? I'm puzzled...
http://en.wikipedia.org/wiki/April_Fools%27_Day_RFC
Also, RFCs are not terribly heavyweight technical documents. They're essentially memos, not ISO standards. Any (demonstrably competent) person can submit a RFC, and if it becomes popular, then the idea enters the standards track, and new, better RFCs are issued based on it.