On Wed, Sep 25, 2013 at 6:24 PM, Dino Bektešević <ljet...@gmail.com> wrote: > > Where did you find that In-Reply-To: field? In example Alan's response > header
Gmail has a "Show original" link in the message drop-down menu. But in this case I just searched the September text archive: https://mail.python.org/pipermail/tutor/2013-September.txt I replied to you using Gmail's "Reply to all" in the webmail interface, which added "In-Reply-To" and "References" to the header. RFC 2822: http://www.ietf.org/rfc/rfc2822.txt The "In-Reply-To:" and "References:" fields are used when creating a reply to a message. They hold the message identifier of the original message and the message identifiers of other messages (for example, in the case of a reply to a message which was itself a reply). The "In-Reply-To:" field may be used to identify the message (or messages) to which the new message is a reply, while the "References:" field may be used to identify a "thread" of conversation. When creating a reply to a message, the "In-Reply-To:" and "References:" fields of the resultant message are constructed as follows: The "In-Reply-To:" field will contain the contents of the "Message- ID:" field of the message to which this one is a reply (the "parent message"). If there is more than one parent message, then the "In- Reply-To:" field will contain the contents of all of the parents' "Message-ID:" fields. If there is no "Message-ID:" field in any of the parent messages, then the new message will have no "In-Reply-To:" field. The "References:" field will contain the contents of the parent's "References:" field (if any) followed by the contents of the parent's "Message-ID:" field (if any). If the parent message does not contain a "References:" field but does have an "In-Reply-To:" field containing a single message identifier, then the "References:" field will contain the contents of the parent's "In-Reply-To:" field followed by the contents of the parent's "Message-ID:" field (if any). If the parent has none of the "References:", "In-Reply-To:", or "Message-ID:" fields, then the new message will have no "References:" field. Note: Some implementations parse the "References:" field to display the "thread of the discussion". These implementations assume that each new message is a reply to a single parent and hence that they can walk backwards through the "References:" field to find the parent of each message listed there. Therefore, trying to form a "References:" field for a reply that has multiple parents is discouraged and how to do so is not defined in this document. _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor