Where to find documentation for "--without-http-cache (disable HTTP cache)"

[Mark Alan]

Igor Sysoev wrote:
> On Tue, Mar 24, 2009 at 11:09:07AM +0000, Mark Alan wrote:
> 
>> Could someone please point me to some documentation about
>> the option --without-http-cache (disable HTTP cache) and the related 
>> module(s)?
> 
> The option just disables building HTTP cache.

What does the HTTP cache option do?
Is there any usage case to show what is its purpose?
Why is it set by default as HTTP_CACHE=YES in the auto/options file?


M.