"It's weird. Both 821 and 822 looooong predate my time on the Internet, and you sort of get used to them being as if written in stone. Doesn't look like the changes were too radical -- mostly just catching them up to current practice -- but that's a lot of text that I haven't got through yet and there's surely some gotchas in there. Does your mail client or server (or netnews client, since they use the message format) comply?
And this is the first time that Jon Postel's name has seemed conspicuously absent to me..."