def METHOD_NAME(read_csv_for_filenames):
    # Construct the output manifest filename from input file keywords
    inst = fits.getval(read_csv_for_filenames[0], "INSTRUME", ext=0).lower()
    root = fits.getval(read_csv_for_filenames[0], "ROOTNAME", ext=0).lower()
    tokens_tuple = (inst, root[1:4], root[4:6], "manifest.txt")
    manifest_filename = "_".join(tokens_tuple)
    print("\nconstruct_manifest_filename. Manifest filename: {}".format(manifest_filename))
    return manifest_filename