I did some testing and I didn't see this information anywhere on the web, so if you can please add it to the page for future reference and education of the masses!
First I wanted to know if I could create two seperate appcaches for one website domain.
=> It looks like that is perfectly possible!
This is important, because I have a dutch and french version, the people visiting the dutch version could have the dutch appcache and vice versa.
I hoped for a moment that the 5MB limit would be per appcache file, but it's not. This is probably per domain.
What also was important is that the caching system is case sensitive!
I use an IIS webserver wich is not, and then I made a 'case sensitivity' error => point proven ;-)
And last but not least: If a page is loaded from the appcache and a resource (image) it needs is not in the appcache, the image is not loaded even if your server is online and you are connected to the internet!!
Thank you for your time, please double check my findings and add them to the wonderfull resource!