Document: FSC-0041
Version:  002
Date:     14-Jul-90




                               MSGID / REPLY
                 A proposal for unique message identifiers
                          and reply chain linkage

                               14 July, 1990

                                 jim nutt
                             1:114/30@fidonet




Status of this document:

     This FSC presents the final draft of a proposed FTSC (FidoNet(r)
     Technical Standards Committee) standard for the FidoNet community
     and requests comments from all interested parties.  Distribution of
     this document is unlimited.

     Fido and FidoNet are registered marks of Tom Jennings and Fido
     Software.


MSGID

     A MSGID line consists of the string "^AMSGID:" (where ^A is a
     control-A (hex 01) and the double-quotes are not part of the
     string),  followed by a space,  the address of the originating
     system,  and a serial number unique to that message on the
     originating system,  i.e.:

          ^AMSGID: origaddr serialno

     The originating address should be specified in a form that
     constitutes a valid return address for the originating network.   
     If the originating address is enclosed in double-quotes,  the
     entire string between the beginning and ending double-quotes is 
     considered to be the orginating address.  A double-quote character
     within a quoted address is represented by by two consecutive
     double-quote characters.  The serial number may be any eight
     character hexadecimal number,  as long as it is unique - no two
     messages from a given system may have the same serial number
     within a very long period of time.  The manner in which this
     serial number is generated is left to the implementor.


REPLY

     A REPLY line consists of the string "^AREPLY:" (where ^A is a
     control-A (hex 01) and the double-quotes are not part of the
     string),  followed by a space, and the origaddr and serialno
     fields of the MSGID line of the message to which this message is a
     reply,  i.e.:

        ^AREPLY: origaddr serialno

     The origaddr and serialno fields must be identical to the
     corresponding fields in the MSGID of the message to which this
     message is a reply.  A REPLY line is never generated in a 
     message that is a reply to a message that does not contain a
     MSGID line.


GENERAL

     For best results,  MSGID and REPLY lines should be the first two
     lines of the message after extended addressing lines (FMPT, TOPT,
     INTL, DOMAIN),  with MSGID appearing above REPLY.

     Finally,  a MSGID is generated only at the time of message
     creation.  An existing MSGID and/or REPLY should never be stripped
     from a message passing through an intermediate system.  No system
     should ever add an MSGID and/or REPLY to,  or modify an existing
     MSGID / REPLY contained in,  a message not originating on that
     system.