RFC 743 (rfc743) - Page 1 of 8

FTP extension: XRSQ/XRCP

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NWG/RFC# 743                                  KLH 30-Dec-77 08:39  42759
Network Working Group                                     K. Harrenstien
Request for Comments: 743                                         SRI-KL
NIC: 42758                                              30 December 1977



                        FTP extension: XRSQ/XRCP




This RFC describes an extension to FTP which allows the user of an ITS
FTP server (i.e. on MIT-(AI/ML/MC/DMS)) to mail the text of a message to
several recipients simultaneously; such message transmission is far more
efficient than the current practice of sending the text again and again
for each additional recipient at a site.

Within this extension, there are two basic ways of sending a single text
to several recipients.  In one, all recipients are specified first, and
then the text is sent; in the other, the order is reversed and the text
is sent first, followed by the recipients.  Both schemes are necessary
becaue neither by itself is optimal for all systems, as will be
explained later.  To select a particular scheme, the XRSQ command is
used; to specify recipients after a scheme is chosen, XRCP commands are
given; and to furnish text, the usual MAIL or MLFL commands apply.

Scheme Selection: XRSQ

   XRSQ is the means by which a user program can test for implementation
   of XRSQ/XRCP, select a particular scheme, reset its state thereof,
   and even do some rudimentary negotiation.  Its format is like that of
   the TYPE command, as follows:

      XRSQ []  = a single character.  The following are defined:
         R  Recipients first.  If not implemented, T must be.
         T  Text first.  If this is not implemented, R must be.
         ?  Request for preference.  Must always be implemented.

         No argument means a "selection" of none of the schemes (the
         default).

      Replies:
         200 OK, we'll use specified scheme.
         215  This is the scheme I prefer.
         501 I understand XRSQ but can't use that scheme.
         5xx Command unrecognized or unimplemented.
         See Appendix A for more about the choice of reply codes.

   Three aspects of XRSQ need to be pointed out here.  The first is that
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