Re: Clarification on cacheability
Roy T. Fielding (fielding@kiwi.ICS.UCI.EDU)
Wed, 22 Dec 1999 11:54:38 -0800
>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.
Rationale: Consider the addition of the 206 status code (partial content).
The contents are cacheable, but only by a cache that understands that
the contents are a splice of the cacheable content and not the content
itself. Thus, unrecognized status code responses must not be cached,
regardless of the presence of cache-control, since the contents of
cache-control are intended for those recipient that do recognize the 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.
....Roy