The header functionality only works if you have enabled the header mod. Refer to your local documentation for more information on how to do this.

For example, the <Location> directive below would add the line Cache-Control: max-age=604800 to every image that comes out of www.mysite.com/AGChannel/images/:

<Location /AGChannel/images/> Header append 
Cache-Control "max-age=604800" </Location>

Likewise, the <Location> directive below would add Cache-Control: max-age=43200 to every Web page that is located in www.mysite.com/AGChannel/articles :

<Location /AGChannel/articles/> Header append 
Cache-Control "max-age=43200" </Location>

What if there is one Web page in the /AGChannel/articles/ directory that should have a shorter cache time? If you follow the previous directive with the <Location> directive below, it won't work:

<Location /AGChannel/articles/hourlynews.html> Header append 
Cache-Control "max-age=3600" </Location>

The <Location> directive above produces the Cache-Control header below:

Cache-Control: max-age=43200, max-age=3600

This is pretty confusing and error-prone, and it is hard to predict which age the proxy server will actually obey. Instead, try something like this:

<Location /AGChannel/articles/> Header append 
Cache-Control "max-age=43200" </Location>

<Location /AGChannel/articles/hourlynews.html> 
Header unset Cache-Control 
Header append Cache-Control "max-age=3600" </Location>

The Header unset Cache-Control directive will remove any and all Cache-Control headers, so that you have a clean slate on which to add your own.