Etag/Last Modified - the numpty question I've always wanted to know.

[Geebee]

Thanks for the great info. I now get the 'unconditional' and 'conditional' bit :-).

Some check questions:
- Etag is difficult to use with a multi-server config, right?
- is the setting Cache-control: public important?
- we use the Cache-control Max-age as an absolute value (600 seconds) instead of a relative value, next to a relative Expire setting. Can that be a problem? Should I fix that? It works well as far as I can see...