RE: Clarification on cacheability

> -----Original Message-----
> From: Roy T. Fielding [mailto:fielding@kiwi.ICS.UCI.EDU]
> Sent: Wednesday, December 22, 1999 11:55 AM
> To: Josh Cohen (Exchange)
> Cc: HTTP-WG (E-mail)
> Subject: Re: Clarification on cacheability 
> 
> 
> >So, my question essentially comes down to this:
> >If I invent a new 3xx status code, or overload an existing 3xx
> >code but I include a cache-control: header to explicitly
> >allow caching, can a cache cache the results?
> 
> Only if the cache recognizes (understands the semantics of) the
> new status code.
> 
> BTW, this is what you want for the WAP answer.  If they try 
> to use anything
> other than a 3xx, they are on their own.
>
Thanks for the response.
So, what do you mean by that?  SHould they re-use a 3xx code that allows
caching ? Which of those would be best ? 
The idea of using 305 Use proxy came up, what do you think of that?

In regard to your 206 rationale..
The 206 is a clear case of why you dont want to cache, but by default
it wouldnt be.  Actively adding cache-control would instruct the cache to
cache it.  However, that would be broken, thus you shouldnt send cache
control
with 206.  In this (the wap case), caching is what you want, so sending a
cache
control would be the desired result if the cache cached it.
If the default is to not cache it, why not allow cache control to 
allow caching if either: the cache understands the response code OR
if the response is safe to cache "in the normal way"?

> ....Roy
>