> There is no good reason to do UA sniffing. That page could simply provide you one of 3 (or more) options to select. So, giving people the correct file instea

> There is no good reason to do UA sniffing. That page could simply provide you one of 3 (or more) options to select. So, giving people the correct file instead of making them know what they need (which many people dont... especially if it is browser specific) is not a good reason? What if a server wants to provide a client with native order endianess (for RPC for example), that shouldnt be allowed? > Date headers are not useful for that purpose. Expiration would be based on the time of the UA, not the one given by a server. Tell that to my browser which countless times doesnt fetch a new file because it has a cached copy. Furthermore, if the headers are stored with the cached copy, there is no server/client time problem because you can calculate the difference between server time and client time. > The session should be ephemeral and not matter anyway, so there is no reason for it to be signed. This is correct in idea, but not in practice. Often times, the server isnt a single server, but rather a set of load-balanced servers. When this happens, it is hard to keep track of client state because a client might get load-balanced to another machine on its next request. Therefore, client state is kept with the client (and signed to make sure that it is legitimate). This sort of behavior has become necessary, although can be better dealt with with some sort of standard (esp. to ensure the protection of the cookie et cetera).