Re: XHR header blacklist rationale

* Julian Reschke wrote:
>Bjoern Hoehrmann wrote:
>> * Julian Reschke wrote:
>>> I also don't see why the client shouldn't have the option to set the 
>>> Expect header; keep in mind that although 100-continue is the only 
>>> expectation code defined in RFC2616, other codes can be defined as well, 
>>> and it's not XHR's business to close that door.
>> 
>> I think whether the client uses `Expect: 100-continue` is a decision
>> similar to deciding whether the client uses, say, a Transfer-Encoding.
>> The client may also be specifically configured to use a different
>> version of the protocol, like IE is configured to talk HTTP/1.0 to
>> proxy servers by default. Besides, the client may not even handle the
>> 100-continue response properly.
>
>What about "Expect: foobar"?

For all we know, `foobar` could be equivalent to 100-continue, in which
case the same considerations apply. I'm perfectly fine if a user agent
recognizes `foobar` and decides to pass the header along, I rather see
the purpose of the list of headers as reminding implementers that they
should make a concious decision with respect to these headers, rather
than simply and blindly block them. Calling it blacklist and embedding
it in SHOULDs and MUSTs does not strike me as useful.
-- 
Björn Höhrmann · mailto:bjoern@hoehrmann.de · http://bjoern.hoehrmann.de
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Received on Tuesday, 27 May 2008 16:18:51 UTC