the drums WG in IETF has recently broken out the syntax part from RFC 822
into a separate document, currently an I-D. We need to keep an eye on how
this develops and potentially change our references when the new draft
becomes an RFC and enters the standards track. The latest draft is:
ftp://ds.internic.net/internet-drafts/draft-ietf-drums-abnf-02.txt
Regards,
Carl-Uno