I've tested multiple sites that I have Quick Cache installed on via Google's PageSpeed Insights tool (http://developers.google.com/speed/pagespeed/insights/), and for all of them it is still suggesting that I "leverage browser caching."
The Google PageSpeed tools suggests "Setting an expiry date or a maximum age in the HTTP headers for static resources instructs the browser to load previously downloaded resources from local disk rather than over the network."
This applies primarily to a small list of graphic files (.png, .jpg, etc...) and on one site a .js file is listed. For each of these items it's telling me "expiration not specified."
Should I be concerned, or can this warning safely be ignored? I'm guessing these are files that Quick Cache is simply not caching?