-&   Create multi-volume archive

  When this option is specified PKZIP will create a .ZIP file which is
  larger than a single floppy disk.  This option may only be specified when
  creating a .ZIP file on removable media (i.e.  a floppy disk or high
  capacity cartridge drive).

  If PKZIP encounters an unformatted floppy disk it will format it before it
  continues.  This means that you will not need to anticipate the exact
  number of floppies that will be needed ahead of time.  For complete
  information on the use of this and related options, please see the PKZIP
  Backup Guide.