Valid characters for network share
Solution 1:
To add a bit of information, localized char, like é, è, à, etc.., in a share name can get non unicode compliant application to behave badly.
In example QuickBook will throw random error while openning a DB on a share with localized char.
As such I suggest to use non localized share name even if technically you can use them.
Solution 2:
Refer to the official microsoft documentation, pretty much all is allowed but slashes, angular brackets etc.
https://docs.microsoft.com/en-us/windows/desktop/fileio/naming-a-file