NixOS on USB with Fat32 partition will NOT boot

NixOS on USB with Fat32 partition will NOT boot on my computer, unless I rename the USB drive from "NIXOS_14.04" to either "NIXOS_1404" or simply: "NIXOS". Why does the version HAVE to be apart of the naming convention of the filesystem? ISO image, sure, but for general compatibility no commas or punctuation signs should be used in naming a partition IF the live media looks for the name of the media in particular.