ietf-nntp Proposed new HDR text

[Jeffrey M. Vinocur]

On Thu, 4 Apr 2002, Charles Lindsey wrote:

> There are essentially two possibilities we are likely to encounter. The
> implementation supports HDR on ALL headers, or it supports just those in
> the Overview.  [...]
>
> Now, if a client is really determined to find all occurrences of some
> obscure header, it can call LIST EXTENSIONS. If it sees "HDR ALL", then it
> can go ahead and use HDR. If it sees "HDR OVERVIEW" then it can have a
> look at OVERVIEW.FMT to see if the header it wants is available.

There is a third possibility which has come up in news.software.nntp
recently in the context of binaries.  The server might support HDR on
certain headers but not want to return them in response to OVER (or list
them in overview.fmt).

Supernews currently does this:  they index all of the MIME headers in an
overview-like fashion, so they can efficiently respond to HDR requests for
them.  But since many clients will make no use of those headers, they
don't include them in OVER.

I don't know if they support HDR on other headers by opening the article,
though.  Probably they do.



-- 
Jeffrey M. Vinocur
jeff at litech.org