A Vary field value of * signals that unspecified parameters not limited to the request-headers (e.g., the network address of the client), play a role in the selection of the response representation. The * value MUST NOT be generated by a proxy server; it may only be generated by an origin server.
A Vary header field-value of * always fails to match and subsequent requests on that resource can only be properly interpreted by the origin server.
Does it means that all items with this header are going to be a cache miss?
I find out that ASP.NET is returning that HTTP header if you use their OutputCacheAttribute, and you have to disable explicitly that behaviour if you don't want the header, or you want to specify custom headers in Vary, so I (want to) believe it is unlikely.
Which is the practical meaning of Vary:* ? And what is the difference between a response with this header and another without the Vary header at all?
Valeriano Tórtola Luis [hidden email]