change 13.7.1

Section 13.7.1  says:

13.7.1 Caching and Status Codes
A response received with a status code of 200, 206 or 301 may be stored
by a cache and used in reply to a subsequent request, subject to the
expiration mechanism, unless a Cache-Control directive prohibits
caching. However, a cache that does not support the Range and
Content-Range headers MUST NOT cache 206 (Partial Content) responses.
A response received with any other status code MUST NOT be returned in a
reply to a subsequent request unless it carries at least one of the
following:
*	an Expires header
*	a max-age Cache-Control directive
*	a must-revalidate Cache-Control directive
*	a public Cache-Control directive

It should say:

13.4 Cachability of Responses
A response received with a status code of 200, 203, 206, 300, 301, or
410 may be stored by a cache and used in reply to a subsequent request,
subject to the expiration mechanism, unless a Cache-Control directive
prohibits caching. However, a cache that does not support the Range and
Content-Range headers MUST NOT cache 206 (Partial Content) responses.

A response received with any other status code MUST NOT be returned in a
reply to a subsequent request unless there are Cache-Control directives
or another header(s) that explicitly allow it. For example, these
include the following: an Expires header (section 14.21); a "max-age",
"must-revalidate", "public" or "private" Cache-Control directive
(section 14.9).


Reasons:
The 203, 300, and 410 status codes are usefully cachable. A "private"
Cache=Control directive is also intended to allow responses to be
cached, accoridng to section 14.9. 

----------------------------------------------------
Paul J. Leach            Email: paulle@microsoft.com
Microsoft                Phone: 1-206-882-8080
1 Microsoft Way          Fax:   1-206-936-7329
Redmond, WA 98052