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
Responding-System: cbosgd.UUCP
cbosgd:osg,cb,btl,bell,net,fa,to,test
ucbvax:net,fa,to.ucbvax:L:
cbosg:net,fa,bell,btl,cb,osg,to.cbosg:F:/usr/spool/outnews/cbosg
cbosgb:osg,to.cbosgb:F:/usr/spool/outnews/cbosgb
sescent:net,fa,bell,btl,cb,to.sescent:F:/usr/spool/outnews/sescent
npois:net,fa,bell,btl,ug,to.npois:F:/usr/spool/outnews/npois
mhuxi:net,fa,bell,btl,ug,to.mhuxi:F:/usr/spool/outnews/mhuxi