mlabel - make an MSDOS volume label
mlabel [ -v ] drive:
Mlabel displays the current volume label, if present, and prompts the user for a new volume label. To delete an existing volume label, press return at the prompt. Mlabel will allow the following command line option: v Verbose mode. Display the new volume label if the label supplied is invalid. Reasonable care is taken to create a valid MSDOS volume label. If an invalid label is specified, mlabel will change the label (and display the new label if the verbose mode is set). Mlabel returns 0 on success or 1 on failure.
mformat(1)