-- `statepath`: Path to a JSON file which stores the last modification time of
- each file; automatically updated by `nsscash`. Used to fetch data only when
- something has changed to reduce the required traffic.
+- `statepath`: Path to a JSON file which stores the last modification time and
+ hash of each file; automatically updated by `nsscash`. Used to fetch data
+ only when something has changed to reduce the required traffic, via
+ `If-Modified-Since`. When the hash of a file has changed the download is
+ forced.