What letters should not start a file name?

Question

cmd/bat

It seems that there are eight characters that the file name should not begin with, I know four of them, but what are the rest?
Tell me please.

Answer 1

In general, the Windows command line is quite capricious to non-alphanumeric characters. And not just at the beginning of a file, but anywhere in a file or directory name.
The symbols listed above by Sergey V cannot be used, because these are cmd.exe special symbols (it is used by it for its own needs), but there are still a bunch of other symbols that are not special symbols, but from which cmd.exe is also distorted. Therefore, the best recommendation here is not to use non-alphanumeric characters in file names at all.
I can also add to the list right off the bat:
! - when using the setlocal enabledelayedexpansion command in a batch file, the exclamation mark becomes a special character
% - inside the batch file it is a special character.
^ - is a special character
Characters that cmd.exe normally transfers: _.,[email protected]#-+=/{}[]'` and space
By the way, the colon seems to be relevant only at the beginning of the file, in any other place - you can use it.
At one time, I had to get around the problem of non-standard characters in cmd.exe, so I know it firsthand.
And yet, problems with symbols appear precisely when applied to cmd.exe batch files, if you have a different task, then perhaps this problem will not be so acute for you.

Answer 2

if it's about this:
https://docs.microsoft.com/en-us/windows/desktop/f...
then there are more than eight