This is most likely due to those names not being allowed for files or folders in the Windows file system. MS Teams channels create a matching folder in SharePoint where file attachments are stored.
Every time, it seemed like it was going to be so easy and powerful. Each time, it turned out to be impossible to implement relatively vanilla functionality.
I worked at a bank that had a windows-based trading system and for some reason created folders to hold the details of each book. There were issues when a trader decided to call a book "LPT1".
I've spent the last 20 years of my career working for investment banks. Never seen a windows based trading system. Frankly picking windows as a target platform for trading infra is asking for trouble. Everyone seems to know that and build on top of Linux. When was that?
No, it's most often not related to any particular client. Rather the book is a list of all buy and sell orders that didn't match sitting there and waiting for someone to take the other side of the trade
\\?\GLOBALROOT\ anyone? Now you're opening devices from the NT object namespace rather than files.
Bonus: You can create the file C:\con\con using NT Native API filesystem calls. Someone even made a video of installing Windows into C:\con\con, and the kernel-side stuff works beautifully, and the explorer shell side dies horribly.
At some point, I think it would only play sound files in the program's folder. I have the vague feeling that it was later changed to an AOL-created subfolder unique to each Windows user.
> AFAIK, everything else is fair game, even emojis
FWIW, I generally expect emojis to be more compatible than other symbols, because they have no legacy meanings - ex. ™ has never been a path separator, or indeed anything else.
Main problem with "emojis" is that they live outside the basic multilingual plane, and so make bad utf-16 handling really obvious. This is a blessing in disguise, because it acts as a no-brown-m&ms thing, since it's more unarguably broken than not being able to use cuneiform, or musical symbols.
And it was merely not recommended to use a fullstop at the start of a filename. Device drivers —perhaps just for storage devices — were usually named this way (and also marked invisible). There was an alleged chance the OS would try to load your non-driver file as a driver for the device it resided on. Though I was unable to make it happen.
NTFS itself has not that many forbidden characters (though ':' is one of them, it denotes alternate stream).
What people think about those CON, PRN, AUX, NUL etc are not filesystem limitation.
And while we are here - nor backslash, nor forward slash are used in NTFS. It can care less about what char do you use for a directory separator. Just be sure to update your APIs.
> [...] and only disallows the ascii slash and null. All other bytes are fair game.
There's also the special treatment of "", ".", and ".." (that is, a file or directory name consisting entirely of zero, one, or two dots), and the convention that a name starting with a dot is hidden.
Yes, and it was an absolutely horrible mistake in the other direction. If I give you a path “./something/example.txt” it could be a file called example.txt in a folder called something or it could be a single file called “something/example.txt”.
Once I planned to share files between a Mac and a Win PC through a product synching folders but gave up very soon due to the constant errors and problems with file names worked in one but not in the other, dominantly filenames that I did not choose but received (e.g. link dragged from address bar to folder, but others too) but some I choose following some preexisting logic.
And matching Active Directory groups. It's kind of cool to use them, because it's a really easy way to let the users administrate access to resources without opening a support ticket.
But it now has a feature to integrate seamlessly with OneDrive, linking or replicating a folder on the user machine. Hence, I expect it has the same limitations in terms of naming.
OneDrive for Business (not consumer!) is SharePoint. It has the same restrictions as SharePoint (nb: because they're separate Web Applications, Microsoft can enable/disable features independently between "OneDrive" and SharePoint).
Yes, OneDrive client is restricted by the Win32 API in terms of allowable file names/path length (which is now 32k but Office doesn't respect MAX_PATH and implements its own ~250 path length limitation).