On Wed, 5 May 2004 [EMAIL PROTECTED] wrote: > Few people know this but Microsoft Internet Explorer and other > major browsers only PRETEND to support "Vary:". > > In MSIE's case... there is only 1 value that you can use with > "Vary:" that will cause MSIE to make any attempt at all to > cache the response and/or deal with a refresh later. > > That value is "User-Agent". > > MSIE treats all other "Vary:" header values as if it > received "Vary: *" and will REFUSE to cache that > response at all.
I did not check the "Vary: User-Agent" header value but as far as I know MSIE 5.5 and 6.x could cache the response with ANY "Vary" header value if that response contains the "Content-Encondig: gzip" or "Content-Encondig: deflate" header. MSIE 4.x and 5.0x could cache such responses only if the URL has a ".html" or ".htm" extentions. There are probably other cachable extentions. MSIE 4.x always sends "If-Modified-Since" for these cached responses. Igor Sysoev http://sysoev.ru/en/
