moinmoin: if you change a folder or file the CID will change, and the old information will still be available.

So if you add to a folder `a` with the file `b` the file `c`, you'll have two versions of the folder locally. The old version with 1 file and the new version with both files.

Since the old file stays the same the overhead is just an old directory listing, with like 2 KByte in size or so.

If someone got the old CID he can still get the old 'version' of the folder, while somebody with the new CID can see both files since he gets the new listing.

The 'garbage' is cleaned up with the garbage collector, which will remove everything which is not pinned or part of the MFS (files tab in the GUI.

When you want to generate static links you create a public/private key pair and can update this link, this system is called IPNS. You can specify the lifetime, the cache time etc on those entries.