I have seen some posts asking how to hide items in DLNA since DLNA has no user authentication. Having not previously been a DLNA user, I couldn't answer. Now, I can make a couple of suggestions:
The only question is, who do you want to hide them from? If you only need to hide them from DLNA users and you don't mind that they are also hidden from you in DLNA, there are two solutions.
The first, and most obvious, is put them in a ahare with DLNA disabled. This is the answer most often given.
There is another way if, for some reason, that doesn't suit you. A folder hidden in Linux (starts with a dot) is hidden in DLNA. And you cannot manually type in the directory name and get there, or anywhere inside, at least on the limited number of devices I've tested with. In Windows, and likely any other device that uses SMB, you can see the folder if you have enabled showing hidden files, and you can always type in the folder name in Windows Explorer. So, as an example, typing \\IP.of.your.NAS\Videos\.hidden in either a Windows Explorer address bar or the Search window will open that folder (assuming you have the proper privilages). But modifying a Windows Explorer title bar that was opened by clicking the DLNA link in "My Computer" by adding the hidden folder )or anyting inside it) will not get you there.
Note that making the folder hidden as a Windows attribute has no effect at all in DLNA.
I assume that the folder will also be hidden in NFS, since it's Linux based. But ls -all shows hidden files and folders in Linux. I don't know about other protocols. I don't know what impact it will have on Mac users, it being Linux based.
A caveat is that you can't create such a folder in Windows. But you can via the NAS UI. Note that when you do so in the UI, it will immediately be hidden, but it's really there. You can also create it via SSH.
Of course, calling is something like .YouAreNotGoingToGuessThis is less likely to be "stumbled on" than .hidden. Still, it's not really secure. You can tie down SMB security by right-clicking on the folder in Windows, selecting the Security tab, and making the changes you need to. But that might not do anythng for anyone using other protocols (NFS, AFP, FTP, etc.). So, still not really secure; but might keep out curious not-so-computer-savy eyes.
