Reserved characters in filenames?

Question:
What are the reserved characters we have to be aware of when naming folders?

Answer:
It depends on the operating system and filesystem-type of the computer.

For example, in Windows, open Windows Explorer, select any file, press F2 to change the filename,
and then try to insert a ‘?’ into the filename. You’ll see a tooltip with the set of characters that Windows does not allow
to be in a filename.