VMS Help SET, QUEUE, Qualifiers, /WSEXTENT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /WSEXTENT=n

    Defines for the batch job a working set extent, the maximum
    amount of physical memory that the job can use. The job uses
    the maximum amount of physical memory only when the system has
    excess free pages. The value set by this qualifier overrides the
    value defined in the user authorization file (UAF) of any user
    submitting a job to the queue.

    Specify the value of n as a number of 512-byte pagelets on Alpha
    or 512-byte pages on VAX. Note that the OpenVMS system rounds up
    this value to the nearest CPU-specific page so that actual amount
    of physical memory allowed may be larger than the specified
    amount on Alpha.

    If you specify the value 0 or NONE, the working set extent value
    defaults to the value specified in the UAF or by the SUBMIT
    command (if included).