John C Klensin wrote:
In Section 4.4 on Trace Information, the "ID" clause of the Received
field is defined as
ID = CFWS "ID" FWS String / msg-id
This is claimed to be inconsistent with RFC 2822, which only permits
"String" is there to provide additional flexibility for gateways, etc.,
for which a message-ID format may not be appropriate, but it has been
suggested that we remove it in the interest of consistency.
Question: Is the production correct as is, or should "String" be
eliminated as a possibility?
Note that, if the answer is "ok as is", we may want to think about
whether we are happy with the syntax in in 2822.
To summarize the comments that have been received onlist:
eliminate string 1
keep string 1
change string to atom 3
If we change string to atom, from the ABNF productions, this would
remove quoted-string from the possibilities for use in Received, but
leave atoms in the production list. Given the examples of real world
data we've seen so far, showing both atoms and msg-ids but not
quoted-strings, this seems reasonable. This is actually a perfect
example where we're narrowing the definition to match what's actually
Unless people can find examples where quoted-strings were actually used,
I would like to close this issue out with the recommendation to change
"string" to "atom".