usefor-article-03 February 2000

5.6.4.  Delimiter Summary

   A summary of the various delimiters. The name immediately to the left
   of the delimiter is always that of the machine which added the
   delimiter.

   '/' The name immediately to the right is known to be the identity of
       the machine from which the article was received (either because
       the entry was made by that machine and we have verified it, or
       because we have added it ourselves).

   '?' The name immediately to the right is the claimed identity of the
       machine from which the article was received, but we were unable
       to verify it (and have prepended our own view of where it came
       from, and then a '/').

   '%' Everything to the right is the pre-injection region followed by
       the tail-entry.  The name on the left is the FQDN of the
       injecting agent. The presence of two '%'s in a path indicates a
       double-injection (see 8.2.2).

   '!' The name immediately to the right is unverified. The presence of
       a '!' to the left of the '%' indicates that the identity to the
       left is that of an old-style system not conformant with this
       standard.

   ',' Reserved for future use, treat as '/'.

   Other
       Old software may possibly use other delimiters, which should be
       treated as '!'.  But note in particular that ':', '-' and '_' are
       components of names, not delimiters, and FWS on its own MUST NOT
       be used as the sole delimiter.

        NOTE: Old Netnews relaying and injecting programs almost all
        delimit Path entries with the '!' delimiter, and these entries
        are not verified. As such, the presence of '%' as a delimiter
        will indicate that the article was injected by software
        conforming to this standard, and the presence of '!' as a
        delimiter to the left of a '%' will indicate that the message
        passed through systems developed prior to this standard. It is
        anticipated that relaying agents will reject articles in the old
        style once this new standard has been widely adopted.