Creates
changes
or deletes the volume label of a disk.

LABEL [drive:][label]
LABEL [/MP] [volume] [label]

drive:          Specifies the drive letter of a drive.
label           Specifies the label of the volume.
/MP             Specifies that the volume should be treated as a
mount point or volume name.
volume          Specifies the drive letter (followed by a colon)

mount point
or volume name.  If volume name is specified

the /MP flag is unnecessary.