INTERNET-DRAFT                               Charles H. Lindsey
Usenet Format Working Group                  University of Manchester
                                             July 2001

5.6.1. Format

5.6.1.  Format
      Path-content        = *( path-identity [FWS] delimiter [FWS] )
                               tail-entry *FWS
      path-identity       = 1*( ALPHA / DIGIT / "-" / "." / ":" / "_" )
      delimiter           = "/" / "?" / "%" / "," / "!"
      tail-entry          = 1*( ALPHA / DIGIT / "-" / "." / ":" / "_" )

        NOTE: A Path-content will inevitably contain at least one path-
        identity, except possibly in the case of a proto-article that
        has not yet been injected onto the network.

        NOTE: Observe that the syntax does not allow comments within the
        Path header; this is to simplify processing by relaying and
        injecting agents which have a requirement to process this header
        extremely rapidly.

   A relaying agent SHOULD NOT pass an article to another relaying agent
   whose path-identity (or some known alias thereof) already appears in
   the Path-content. Since the comparison may be either case sensitive
   or case insensitive, relaying agents SHOULD NOT generate a name which
   differs from that of another site only in terms of case.

   A relaying agent MAY decline to accept an article if its own path-
   identity is already present in the Path-content or if the Path-
   content contains some path-identity whose articles the relaying agent
   does not want, as a matter of local policy.

        NOTE: This last facility is sometimes used to detect and decline
        control messages (notably cancel messages) which have been
        deliberately seeded with a path-identity to be "aliased out" by
        sites not wishing to act upon them.

Diffs to previous draft

--- {draft-04}	Wed Jul 11 21:55:25 2001
+++ {draft-05}	Wed Jul 11 21:55:25 2001
@@ -1,5 +1,4 @@
 
5.6.1.  Format
-
       Path-content        = *( path-identity [FWS] delimiter [FWS] )
                                tail-entry *FWS
       path-identity       = 1*( ALPHA / DIGIT / "-" / "." / ":" / "_" )