Why Base91? Because it’s a perfect fit for encrypted file names, producing strings that can be stored as valid files on Unix and macOS.

Base84 is the most efficient file name using the maximum amount of compatible characters.

The alphabet is: ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!#$%&'()+,-;=@[]^_{}~`