Nobody else really uses them to the extent Apple does, but this sort of thing isn&#x27;t unique to HFS+.<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Extended_file_attributes" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Extended_file_attributes</a><p>You can do the exact same thing on Windows (on an NTFS volume), just go to a command prompt and run &quot;notepad hello.txt:secret&quot; and see how DIR and Windows Explorer deal with it.