I've just upgraded a large inherited Tomcat5 app server to Tomcat6. In the TC5 config there was a disableProxyCaching="true" parameter on one of the Context tags, but this doesn't appear to be available in Tomcat6. It's not listed in the TC5 config reference either, but was being silently tolerated, whereas TC6 issues a warning.
I presume this controls whether Tomcat writes HTTP cache-control headers. A search of the online Tomcat6 docs didn't turn up anything. Is this available in another form in Tomcat6, and if so, where?
Turns out disableProxyCaching was left over from a previous maintainer's attempt to influence caching without understanding the details. It's an attribute of authenticator valves, not the Context.