/check/referer should disallow caching

Hi,

sorry if this has been suggested before -- the search
mechanism for the www-validator archives is down and
I don't feel like browsing to see if I find this in
the archives somewhere!

The /check/referer functionality on validator.w3.org,
neat as it is, does not specify any cache-controlling
HTTP headers or meta elements (other than the Date
header). This leads smart caching clients (such as
Opera) to display cached copies if the validator is
used from different pages in a short time span. At
best, this is inconvenient (e.g. one has to manually
clear the cache or reload), at worst it is misleading
(e.g. just now it led me to suspect the wrong page of
being invalid). Adding the header (or http-equiv meta)
Cache-Control: no-cache, and also Pragma: no-cache to
support HTTP/1.0 clients, would resolve this easily,
as far as I can see.

Cheers,

    - Gulli