/DEVICE=device-name
Specifies the name of the user's default device at login. The
device-name is a string of 1 to 31 alphanumeric characters. If
you omit the colon from the device-name value, AUTHORIZE appends
a colon. The default device is SYS$SYSDISK.
If you specify a logical name as the device-name (for example,
DISK1: for DUA1:), you must make an entry for the logical name in
the LNM$SYSTEM_TABLE in executive mode by using the DCL command
DEFINE/SYSTEM/EXEC.