Internet-Draft                              Alfred S. Gilman
draft-gilman-news-url-01
March 4, 1998
Expires six months after above date

                       The 'news' URL scheme

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Abstract

This document defines the format of Uniform Resource Locators
(URLs) identifying news messages and groups.  The syntax of
'news' URLs from RFC 1738 is extended to allow specification of
the site from which the message is to be sought and to
incorporate protections via 'snews' URLs.  This combines into the
'news' scheme enough capability so that the previously-proposed
'nntp' scheme can be retired and URL usage simplified.

. Introduction

The news URL scheme is used to designate a message or a set of
messages circulating through the Internet by methods compatible
with the practices followed by the Usenet community.  In its
simplest form, a news URL contains a Usenet newsgroup name.

Further capabilities are the ability to designate an unique
message as the located resource, to specify that the News server
at a particular site is to be queried for the resource identified
and to request secure dialog via the variant snews scheme name.

This draft is one of a suite of documents intended replace RFC
 [3], "Uniform Resource Locators", and RFC 1808 [4],
"Relative Uniform Resource Locators".  The suite is composed of a
general document [RFC URI SYNTAX] for all URL schemes and
scheme-specific documents for each scheme.

. Syntax of a news URL

Following the syntax conventions of [RFC URL SYNTAX], a news
URL has the form:

   newsURL      =  scheme ":" [ news-server ] [ refbygroup | message ]
   scheme       =  "news" | "snews" | "nntp"
   news-server  =  "//" server "/"
   refbygroup   = group [ "/" messageno [ "-" messageno ] ]
   message      = local-part "@" domain

Sites take the form defined for the generic URL syntax in section
3.2.2 of [RFC-URI-SYNTAX].  Messages take the form specified for
the value of a Message-ID field in RFC 822 [1] or RFC 1036 [2],
without the leading "<" or trailing ">".

Note that the refbygroup and message cases are distinguished by
the absense in the first case and presence in the latter case of
one and only one commercial at sign "@".

Groups take the form of a dotted name of a News group as allowed
in the value of the Newsgroups header field defined in RFC 1036.
Messagenos take the form of an integer message number as numbered
by a particular server.  As these numbers will vary between
copies of the same message available from different servers,
reference by message ID is preferred to reference to messages by
means of these numbers.

Note that all URLs of this scheme are in the category of absolute
URLs, in the terms of [RFC URI SYNTAX].

. Semantics and operations

When the scheme is news, the default port (in server) is 119.
When the scheme is snews, the default port (in server) is 563.

A news URL designates a message or message-carrying subchannel
known as a newsgroup.  When a news URL is activated, message
reading and writing from and to News is initiated, if that
service is available.

If an individual message has been identified, interaction starts
by reading that message.  If an individual group or range of
messages in such a group had been identified, interaction starts
by reading an index of messages.  If no message or group is
identified, interaction starts by reading an index of groups.  No
immediate write or PUT of a message is performed when a news URL
is activated.

Note that user agents may extend the ability to refer to groups
by use of "*" as a string wild-card.

. Examples

An URL to read a newsgroup from anywhere (usually locally):

    <news:alt.adoptive.parenting>

An URL to read a specific message from anywhere (usually locally):

    <news:EFGJG4.7A@deshaw.com>

An URL to read a specific message from a designated site:

    <news://binky.capnet.state.tx.us/5rb1or$67v@news.jumpnet.com>

An URL to read a newsgroup from a designated site:

    <news://adenine.c.dna.affrc.go.jp/misc.transport.air-industry.cargo>

. Acknowledgements

This document was derived from RFC 1738 [3]; the acknowledgements
from that specification still apply.

. References

[] Crocker, D., "Standard for the Format of ARPA Internet Text
Messages", RFC 822, University of Delaware, August 1982.

[] Horton, M. and R. Adams, "Standard For Interchange of USENET
Messages", RFC 1036, AT&T Bell Laboratories, Center for Seismic
Studies, December 1987.

[] Berners-Lee, T., Masinter, L., and M. McCahill, Editors,
"Uniform Resource Locators (URL)", RFC 1738, CERN, Xerox
Corporation, University of Minnesota, December 1994.

[] Fielding, R., "Relative Uniform Resource Locators", RFC 1808,
UC Irvine, June 1995.

[RFC-URI-SYNTAX] Berners-Lee, T., Fielding, R., Masinter L.,
"Uniform Resource Locators (URL): Generic Syntax and Semantics",
Work in Progress <draft-fielding-uri-syntax-02>, MIT/LCS,
U.C. Irvine, Xerox Corporation, Mar 1998.

Appendix

A. Changes from RFC 1738

RFC 1738 defined two distinct URL schemes designated news and
nntp.  Both schemes, however, accessed the same pool of News
message traffic.  In no case was the scheme name significant in
distinguishing references to different messages or to different
groups.  Various implementations have blurred the distinction by
extending the syntax of news to include explicit remote
references including designation of a site.

This draft provides a unified syntax for a graceful migration
to the use of news and snews and not nntp as scheme names.

B. Author contact information:

Alfred S. Gilman
 S. Arlington Ridge Rd.
Unit 712
Arlington VA     22202-1926
asgilman@access.digex.net