Optional. Default: /STRUCTURE=2

    Specifies whether the volume should be formatted in Files-11 On-
    Disk Structure Level 2 (ODS-2), which is the default, or Files-11
    On-Disk Structure Level 5 (ODS-5).

    For more information about ODS-5 disks, refer to the HP OpenVMS
    System Manager's Manual: Essentials.