Authoritative caches

 
Section 2.4.4 refers to the `asynchronous nature' of HTTP messages. This
description is confusing, seeing as HTTP is a synchronous, pipelined
protocol. Also, it isn't really clear when it is permissible for a client
to ignore the server's caching directives or why this is necessary.
 
The `max-age' facility already offers a solution to this problem: express
expiry in TAI seconds from the time of the original response. This solution
is easier to implement than anything involving UTC and requires no clock
synchronization at all.
 
The issue of (potentially large) network latency shouldn't be an issue
because of the way clients determine whether a cached resource is fresh.
 
^L