MBRFormat does not appear to be a valid volume name for its file system

Question

I am using macOS Mojave 10.14.6. I am trying to re-format my USB to FAT. I am getting this error MBRFormat does not appear to be a valid volume name for its file system. What does it mean and how to fix it? Why does file system says "None"?

root$ diskutil info /dev/disk5
   Device Identifier:         disk5
   Device Node:               /dev/disk5
   Whole:                     Yes
   Part of Whole:             disk5
   Device / Media Name:       Cruzer Facet

   Volume Name:               Not applicable (no file system)
   Mounted:                   Not applicable (no file system)
   File System:               None

   Content (IOContent):       GUID_partition_scheme
   OS Can Be Installed:       No
   Media Type:                Generic
   Protocol:                  USB
   SMART Status:              Not Supported

   Disk Size:                 8.0 GB (8004304896 Bytes) (exactly 15633408 512-Byte-Units)
   Device Block Size:         512 Bytes

   Read-Only Media:           No
   Read-Only Volume:          Not applicable (no file system)

   Device Location:           External
   Removable Media:           Removable
   Media Removal:             Software-Activated

   Virtual:                   No

root$ sudo diskutil eraseDisk FAT32 MBRFormat /dev/disk5
Password:
MBRFormat does not appear to be a valid volume name for its file system

Is it already FAT formatted?

/dev/disk5 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *8.0 GB     disk5
   1:       Microsoft Basic Data MyDrive                 7.8 GB     disk5s2

Answer 1

THE_NAME should be written in uppercase.

sudo diskutil eraseDisk FAT32 "THE_NAME" MBRFormat /dev/disk5

Answer 2

You are missing a (new) volume name after the format

sudo diskutil eraseDisk FAT32 THE_NAME MBRFormat /dev/disk5

For further info about its usage:

sudo diskutil eraseDisk
Usage:  diskutil eraseDisk format name [APM[Format]|MBR[Format]|GPT[Format]]
        MountPoint|DiskIdentifier|DeviceNode