Padraic Brady has posted two more updates in his "Zend Framework Page Caching" series - an "A" and "B" for the third part looking at tagging the static files you've cached from the output of your pages.
Expiring multiple caches linked to a specific change is easy to accomplish using Tagging, where we tag caches with keywords and clean caches based on those keywords. Unfortunately, static files can't be tagged in the normal way since their filenames must be constant. [...] In a sense, we're creating a cache within a cache.
The first part of this look at static caching looks at how to integrate a caching component, one that supports tags, into a Zend Framework structure. In the second part he takes it one step further and makes some changes to refactor and clean up some of the Cleaner component's code.