andjor,

Just a guess: same naming convention as for a normal file in a directory/folder of Windows. This as when the file is checked out (it is then in your temporary folder) it should follow the operating system naming conventotions.

So I would suggest to read https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file

Somewhere in the middle is a list of character that one shouldn’t use.

Steve

It should be avoided in document class, number and title, I personally think, but we do remove illegal characters before we try to write files to your PC, so in a way you should not have to worry about it. We remove what Windows consider illegal.

But, you'll have a happier life staying away from these characters...