cancel 

If an article with the given message ID is present on  the
local  system,  the  article is cancelled.  This mechanism
allows a user to cancel an article after the  article  has
been distributed over the network.

Only the author of the article or the local super user  is
allowed  to  use  this  message.  The verified sender of a
message is the Sender  line,  or  if  no  Sender  line  is
present, the From line.  The verified sender of the cancel
message must be the same as  either  the  Sender  or  From
field  of  the original message.  A verified sender in the
cancel message is allowed to match an unverified  From  in
the original message.

3.2  Ihave/Sendme

     ihave <message ID list> 
     sendme <message ID list> 

This message is part  of  the   "ihave/sendme"   protocol,
which  allows  one  site  (say  "A")  to tell another site
("B")  that  a particular message has been received on  A.
Suppose  that site A receives article  "ucbvax.1234",  and
wishes to transmit the article to site  B.   A  sends  the
control  message   "ihave  ucbvax.1234  A"   to site B (by
posting it to newsgroup  "to.B").   B  responds  with  the
control  message   "sendme  ucbvax.1234  B"  (on newsgroup
to.A) if it has not already received  the  article.   Upon
receiving the Sendme message, A sends the article to B.

This protocol can be used to cut down on redundant traffic
between  sites.  It is optional and should be used only if
the particular situation makes it worthwhile.  Frequently,
the  outcome  is  that,  since  most original messages are
short, and since there is a high overhead to start sending
a  new  message  with  UUCP,  it costs as much to send the
Ihave as it would cost to send the article itself.

One possible solution to this overhead problem is to batch
requests.   Several  message  ID's  may  be  announced  or
requested in one message.  If no message ID's  are  listed
in  the control message, the body of the message should be
scanned for message ID's, one per line.



                          - 11 -
 


3.3  Newgroup

     newgroup 

This control message creates a new newsgroup with the name
given.  Since no articles may be posted or forwarded until
a newsgroup is created, this message is required before  a
newsgroup  can  be  used.   The  body  of  the  message is
expected to be a short paragraph describing  the  intended
use of the newsgroup.

3.4  Rmgroup

     rmgroup 

This message removes a  newsgroup  with  the  given  name.
Since  the  newsgroup  is  removed  from every site on the
network, this  command  should  be  used  carefully  by  a
responsible administrator.

3.5  Sendsys

     sendsys (no arguments)

The   "sys"   file,  listing  all  neighbors   and   which
newsgroups  are  sent  to each neighbor, will be mailed to
the author of the control message (Reply-to,  if  present,
otherwise  From).   This  information is considered public
information, and it is  a  requirement  of  membership  in
USENET  that  this  information  be  provided  on request,
either automatically in response to this control  message,
or  manually,  by mailing the requested information to the
author of the message.  This information is used  to  keep
the  map  of  USENET  up  to  date, and to determine where
netnews is sent.

The format of the file mailed back to the author should be
the same as that of the  "sys"  file.  This format has one
line per neighboring site (plus one  line  for  the  local
site),  containing four colon separated fields.  The first
field has the site name of the neighbor, the second  field
has  a newsgroup pattern describing the newsgroups sent to
the neighbor.  The third and fourth fields are not defined
by this standard.  A sample response:

     From cbosgd!mark  Sun Mar 27 20:39:37 1983
     Subject: response to your sendsys request
     To: mark@cbosgd.UUCP