mail headers (was: Re: Z80 CLK DRV)

It was thus said that the Great Oliver Lehmann once stated: And just in case someone complains about this being a very recent development, the "Referenes:" header was first mentioned in RFC-680 (1975---makes no reference to number of references allowed, but does state any that any that are listed to be enclosed in angle brackets). RFC-724 (1977) futher defines the "References:" header, as having the ability to include multiple references: <extension-field> ::= "In-Reply-To" ":" <reference-list> | "Keywords" ":" <phrase-list> | "Message-Id" ":" <mach-host-phrase> | "References" ":" <reference-list> | "Subject" ":" <text-line> | "Comments" ":" <text-line> | <user-defined-field> <reference-list> ::= <null> | <reference-item> | <reference-item> "," <reference-list> <reference-item> ::= <phrase> | <mach-host-phrase> <mach-host-phrase>::= "<" <host-phrase> ">" (<phrase> definition omitted). So it's a pretty old idea ... [1] -spc (RFC-822 is the fifth RFC on an email format ... ) [1] In fact, for a personal project I delved into the history of Inernet based email and as far as I know, the first RFC dealing with electronic email is RFC-561 (1973) that pretty much defines the overall format for Internet releated text messages every since (headers, blank line, body, etc.). It only defined three headers (From, Date and Subject) but you have to start somewhere ...