/SOURCE=device-name:[directory-name]
    Specifies the disk and directory where the utility searches for
    the software product kit or kits. If /SOURCE is not specified,
    the utility searches in the location that the logical name
    PCSI$SOURCE defines. If PCSI$SOURCE is not defined, and the
    /SOURCE qualifier is not specified, PCSI searches the current
    default directory.
    The /SOURCE and /FROM=PDB qualifiers are mutually exclusive.