You can use any combination of upper- or lowercase letters, numbers, and underscores ("_") when naming your subdirectory. Do not include spaces or special characters.

Also, just like file names, subdirectory names are case sensitive (in other words, "subdirectory_1" is not the same as "Subdirectory_1"). We recommend using all lowercase letters in your file and folder names to avoid any problems when you create links that reference these names.