[NNTP] Notes on auxiliary documents

[Russ Allbery]

Ken Murchison <ken at oceana.com> writes:
> Clive D.W. Feather wrote:

>> Section 2.3.2 gives too much emphasis on non-conforming
>> implementations. Replace it completely with something very similar to:

>>     On a server which conforms to this specification, the MODE STREAM
>>     command MUST return a 203 response (or 501 if an argument is given)
>>     and MUST NOT have any other effect.

>>     Historic note: some old server implementations did not advertise
>>     streaming in the response to LIST EXTENSIONS but provided CHECK and
>>     TAKETHIS commands similar or identical to those in this document.
>>     Clients could test for this by issuing the MODE STREAM command; if
>>     it succeeded, pipelining was possible. However, even if the command
>>     succeeded it does not mean that the CHECK and TAKETHIS commands
>>     conform to this specification. Clients SHOULD use the CAPABILITY
>>     command to determine server capabilities.

> First off, I think Russ signed off on the current text, but I'm willing
> to clarify if needed.  In fact, I like most of what you have above.

> This is a similar situation to MODE READER.  We are trying to steer new
> implementations away from MODE STREAM but document its prior use.

> Russ, can you provide some guidance?

MODE STREAM is different than MODE READER; MODE READER is something that
we don't yet have a way of getting rid of entirely (unless you all have
come up with something; I'm massively behind but trying to catch up
tonight).  MODE STREAM, on the other hand, we're explicitly making
obsolete.  The only reason why it's included at all is for
interoperability with existing deployed servers.  As soon as everyone
updates to NNTPv2 servers, it can be dropped completely.

>> In the following paragraph, surely "MUST discard" should be "SHOULD NOT
>> rely on", since the client can still make heuristic decisions.

> I'm not sure about this.  Based on Mark's comments from the MODE READER
> thread, I *think* that this is almost a requirement of TLS (whether
> implicitly or explicity, I don't know).

> Russ, guidance?

How about MUST NOT rely on?  I think we're just trying to find wording
here that doesn't get us into trouble.

-- 
Russ Allbery (rra at stanford.edu)             <http://www.eyrie.org/~eagle/>