VMS Help System Services, $PROCESS SCAN, Arguments  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 pidctx

    OpenVMS usage:process_id
    type:         longword (unsigned)
    access:       modify
    mechanism:    by 32- or 64-bit reference (Alpha)
    mechanism:    by 32-bit reference (VAX)
    Context value supplied by $PROCESS_SCAN to be used as the pidadr
    argument of $GETJPI. The pidctx argument is the 32-bit address
    (on VAX systems) or the 32- or 64-bit address (on Alpha systems)
    of a longword that is to receive the process context longword.
    This longword normally contains 0 or a previous context. If it
    contains a previous context, the old context is deleted. If it
    contains a value other than 0 or a previous context, the old
    value is ignored.

 itmlst

    OpenVMS usage:32-bit item_list_3 or 64-bit item_list_64b
    type:         longword (unsigned) for 32-bit; quadword (unsigned)
                  for 64-bit
    access:       read only
    mechanism:    by 32- or 64-bit reference (Alpha)
    mechanism:    by 32-bit reference (VAX)
    Item list specifying selection criteria to be used by the scan or
    to control the scan.

    The itmlst argument is the 32-bit address (on VAX systems) or
    the 32- or 64-bit address (on Alpha systems) of a list of item
    descriptors, each of which describes one selection criterion or
    control option. Within each selection criterion you can include
    several item entries. An item list in 32-bit format is terminated
    by a longword of 0; an item list in 64-bit format is terminated
    by a quadword of 0. All items in an item list must be of the same
    format-either 32-bit or 64-bit.

    The information in the item list is passed to the item descriptor
    in one of two ways. If the item descriptor can always hold the
    actual value of the selection criterion, the value is placed in
    the second longword of the item descriptor and the buffer length
    is specified as 0. If the item descriptor points to the actual
    value of the selection criterion, the address of the value is
    placed in the second longword of the item descriptor and you must
    specify the buffer length for the selection criterion. Each item
    code description specifies whether the information is passed by
    value or by reference.

    Refer to the OpenVMS System Services Reference Manual to view the
    item code diagrams and descriptor fields tables.