News
The news locators refer to either
news group names or article message
identifiers which must conform to
the rules for a Message-Idof RFC 1036 (Horton 1987). A message
identifier may be distinguished from
a news group name by the presence
of the commercial at "@" character.
These rules imply that within an
article, a reference to a news group
or to another article will be a valid
URL (in the partial form).
A news URL may be dereferenced using
NNTP (RFC977, Kantor 86) (The ARTICLE
by message-id command ) or using
any other protocol for the conveyance
of usenet news articles, or by reference
to a body of news articles already
received.
Note1:
Among URLs the "news" URLs are anomalous
in that they are location-independent.
They are unsuitable as URN candidates
because the NNTP architecture relies
on the expiry of articles and therefore
a small number of articles being
available at any time. When a news:
URL is quoted, the assumption is
that the reader will fetch the article
or group from his or her local news
host. News host names are NOT part
of news URLs.
Note 2:
An outstanding problem is that the
message identifier is insufficient
to allow the retrieval of an expired
article, as no algorithm exists for
deriving an archive site and file
name. The addition of the date and
news group set to the article's URL
would allow this if a directory existed
of archive sites by news group. Suggested
subject of study in conjunction with
NNTP working group. Further extension
possible may be to allow the naming
of subject threads as addressable
objects.