Re: I-D ACTION:draft-resnick-2822upd-01.txt

Frank Ellermann <[email protected]> writes:

> For the <msg-id> I'd like to see a syntax also working in NetNews, in
> news URIs, and in Archived-At links when they use a Message-ID.

For completeness, here's what RFC 3977 says about message IDs as used in
the NNTP protocol:

A.2.  Message-IDs

   Every article handled by an NNTP server MUST have a unique
   message-id.  For the purposes of this specification, a message-id is
   an arbitrary opaque string that merely needs to meet certain
   syntactic requirements and is just a way to refer to the article.

   Because there is a significant risk that old articles will be
   reinjected into the global Usenet system, RFC 1036 [RFC1036] requires
   that message-ids are globally unique for all time.

   This specification states that message-ids are the same if and only
   if they consist of the same sequence of octets.  Other specifications
   may define two different sequences as being equal because they are
   putting an interpretation on particular characters.  RFC 2822
   [RFC2822] has a concept of "quoted" and "escaped" characters.  It
   therefore considers the three message-ids:

      <[email protected]>
      <"ab.cd"@example.com>
      <"ab.\cd"@example.com>

   as being identical.  Therefore, an NNTP implementation handing email
   articles must ensure that only one of these three appears in the
   protocol and that the other two are converted to it as and when
   necessary, such as when a client checks the results of a NEWNEWS
   command against an internal database of message-ids.  Note that
   RFC 1036 [RFC1036] never treats two different strings as being
   identical.  Its successor (as of the time of writing) restricts the
   syntax of message-ids so that, whenever RFC 2822 would treat two
   strings as equivalent, only one of them is valid (in the above
   example, only the first string is valid).

-- 
Russ Allbery ([email protected])             <http://www.eyrie.org/~eagle/>