(Windows) NTFS has hard links which are multiple pointers to the same file, but I imagine that the strict separation between FSes that made it possible in NT is

(Windows) NTFS has hard links which are multiple pointers to the same file, but I imagine that the strict separation between FSes that made it possible in NT is also the reason why Unix, which has a single arbitrary hierarchy, doesn't have hard links.* * Yes there are hard links, but the single hierarchy means that unless you memorised the specific FS of each folder, it's gonna be hard.