[http 1.1] M-POST w3
5. Mandatory HTTP Requests
An HTTP request is called a mandatory request if it includes at least
one mandatory extension declaration (using the Man or the C-Man header
fields). The method name of a mandatory request MUST be prefixed by
"M-". For example, a client might express the binding rights-
management constraints in an HTTP PUT request as follows:
M-PUT /a-resource HTTP/1.1
Man: "http://www.copyright.org/rights-management"; ns=16
16-copyright: http://www.copyright.org/COPYRIGHT.html
16-contributions: http://www.copyright.org/PATCHES.html
Host: www.w3.org
Content-Length: 1203
Content-Type: text/html
<!doctype html ...
https://www.w3.org/Protocols/HTTP/ietf-ext-wg/draft-frystyk-http-extensions-03
x x x
5.1 Fulfilling a Mandatory Request
A server MUST NOT claim to have fulfilled any mandatory request unless
it understood and obeyed all the mandatory extension declarations in
the request. This section defines a mechanism for conveying this
information to the client in such a way that it interoperates with
existing HTTP applications and prevents broken servers from giving the
false impression that an extended request was fulfilled by responding
with a 200 (Ok) response without understanding the method.
If any end-to-end mandatory extension declarations were among the
fulfilled extensions then the server MUST include an Ext response
header field in the response. In order to avoid that the Ext header
field inadvertently is cached in an HTTP/1.1 cache, the response MUST
contain a no-cache cache-control directive. If the response is
otherwise cachable, the no-cache cache-control directive SHOULD be
limited to only affect the Ext header field:
HTTP/1.1 200 OK
Ext:
Cache-Control: no-cache="Ext"
...
If the mandatory request has been forwarded by an HTTP/1.0
intermediary proxy then this is indicated either directly in the
Request-Line or by the presence of an HTTP/1.1 Via header field. In
this case, the server MUST include an Expires header field with a date
equal to or earlier than the value of the Date header field. If the
response is otherwise cachable by HTTP/1.1 caches, the server SHOULD
include an appropriate max-age cache-control directive:
HTTP/1.1 200 OK
Date: Sun, 25 Oct 1998 08:12:31 GMT
Expires: Sun, 25 Oct 1998 08:12:31 GMT
Ext:
Cache-Control: no-cache="Ext", max-age=3600
...
If any hop-by-hop mandatory extension declarations were among the
fulfilled extensions then the server MUST include a C-Ext response
header field in the response. The C-Ext header field MUST be protected
by a Connection header field (see [5], section 14.10).
HTTP/1.1 200 OK
C-Ext:
Connection: C-Ext
Frystyk, et al [Page 9]
INTERNET-DRAFT HTTP Extensions Wed, Jan 20, 1999
Note, that the Ext and C-Ext header fields are not mutually exclusive;
they can be both be present in a response when fulfilling mandatory
request containing both hop-by-hop as well as end-to-end mandatory
extension declarations.
https://www.w3.org/Protocols/HTTP/ietf-ext-wg/draft-frystyk-http-extensions-02
