What character sequence should I not allow in a filename?

Question

I found out after testing that linux allows any character in a file name except for / and null (\\0). So what sequence should I not allow in a file

Answer 1

Are you developing an application where you have to ask the user to create files themselves? If that's what you are doing, then you can set the rules in your application. (eg only allow [a-zA-Z0-9_.] and reject the rest of special characters.) this is much simpler to enforce.