I-D ACTION:draft-ietf-nntpext-base-06.txt

[Thomas Gschwind]

On Fri, 6 Nov 1998, Charles Lindsey wrote:

> In 9.1, "the server SHOULD allocate the next sequential number" and in
> 9.1.1.1 "reinstatement of the previous article, not a new article reusing
> the number". These both conflict with the intention on the USEFOR group to
> introduce a Replace command in addition to the present Supersedes. So it
> would be better to adjust those sentences. It should cause no problem to
> existing implementations.
It might cause problems to existing implementations:
* It keeps the low watermark down. This might be a problem for
  newsreaders that use an array to maintain read articles or overview
  records.
* The estimation of the number of unread articles would be highly in
  error.

And it raises other problems:
* How could the news server implement a wrap around of the watermarks
  then? Are the low/high watermarks increasing indefinitely?
* What happens when an article has already been removed on my news
  server and the low watermark has been increased accordingly?
* It would allow people to miss the article.
  - The original article was expired and thus marked as read by my news
    reader.
  - Now the article is reinstated with the old number.
  - How can my news reader identify this.
* There are two cache servers for News available: nntpcache and 
  NewsCache. Both assume that an article does not change over time.  
  What should they do? 

As far as I understood, the primary intent is that an article I have
read already should not reappear as unread.  Wouldn't it be easier to
require the reading agent to check whether the superseded article has
already been read? This could be easily implemented by using the Xref
header of the superseded article! 

> In the NEWNEWS command, I want to be able to say
> 	...news.admin,!news.admin.lists,...
> Hopefully, allowing '!' in wildmats will fix this, but I should like to
> see some wording.
This is also interesting for the list active and newgroups commands (and
most probably other commands accepting a wildmat expression).

--
Thomas Gschwind                      Email: tom at infosys.tuwien.ac.at
Distributed Systems Group            Tel: +43(1)58801x18412
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