ietf-nntp LIST EXTENSIONS non-pipelined and non-cacheable?

[Russ Allbery]

Clive D W Feather <clive at demon.net> writes:

> Proposed change: current text (this has recently changed for other
> reasons):

>     An NNTP client MUST NOT cache (for use in another session) any
>     information returned if the LIST EXTENSIONS command succeeds.
>     That is, an NNTP client is only able to get the current and correct
>     information concerning available extensions at any point during a
>     session by issuing a LIST EXTENSIONS command at that point of that
>     session and processing the response, and the server MUST ensure that
>     those extensions currently listed in the returned information are
>     available.
>     [...]

> becomes:

>     An NNTP client is only able to get the current and correct
>     information concerning available extensions at any point during a
>     session by issuing a LIST EXTENSIONS command at that point of that
>     session and processing the response, and the server MUST ensure that
>     those extensions currently listed in the returned information are
>     available.
>     [...]
>     An NNTP client MUST NOT rely on any cached results from this command,
>     either earlier in this session or in a previous session, remaining
>     correct. While some extensions are likely to be always available or
>     never available, others will "appear" and "disappear" depending on
>     other changes.

I think the new proposed wording is clearer and still tells client authors
what they need to know.  Ken, does the new wording seem okay to you?  I
think changing from MUST NOT cache to MUST NOT rely on cache is actually a
better reflection of what we want from the client authors.

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