FAQ: Browser Cache
Entity tags were created to add more reliability to client side caching my providing a simple method for a browser to verify that a file had not changed since last it was downloaded. Using them helps enables your server return 304 or "not modified" responses instead of a 200 "ok" response which are much much slower (because the file is sent). The result is a visitor viewing multiple pages of your site would have that "instant loading" experience that we all definitely enjoy. Don't worry we don't use inodes to create our ETags so this solution is reliable for multi server hosting solutions.
Yes, we have ETags covered. Even if you have a clustered hosting environment, your Etags will be consistent (across multiple servers in your cluster) so you don't have to worry about using special session cookies when you introduce our plugin. If you would like to specify headers for various reasons, you can do that as well.
We recommend UTF-8, but we do not modify the encoding in any files, instead we simply return the code as it is provided.