<i>&gt;As for an example of them being helpful - on Windows when you download a file from the Internet using a browser an extended attribute is used to mark that.</i><p>One maybe lesser-known use for ADS: FlylinkDC++ (and derivatives) have an option to store TTH hash data in the file&#x27;s own ADS, instead of in a central hash store. It means that the hash data could be used by multiple applications, but, it&#x27;s less I&#x2F;O efficient to make thousands of these &lt;4KB blocks everywhere.