what if the manifest.appcache is content addressable ? e.g. manifest-[version-number].appcache the appcache semantics are convoluted enough that I must admit I don't know what would happen. Would you visit index.html and it loads the old version of index.html linking to the old version of the cache manifest-- forever?

Perhaps the old version of the manifest gets a comment incremented to force the browser to update index.html? or some tricky javascript forces it? Either way it seems, naively like you could link an index.html version to a manifest version via the manifest's filename.