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

 itmlst

    OpenVMS usage:item_list_3
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    Protection attributes of the object and the rights and privileges
    of the accessor. The itmlst argument is the address of an item
    list of descriptors used to specify the protection attributes of
    the object and the rights and privileges of the accessor.

    Refer to the OpenVMS System Services Reference Manual to view the
    item code diagram and descriptor fields table.

    Specifying any specific protection attribute causes that
    protection check to be made; any protection attribute not
    specified is not checked. Rights and privileges specified are
    used as needed. If a protection check requires any right or
    privilege not specified in the item list, the right or privilege
    of the caller's process is used.

 objpro

    OpenVMS usage:char_string
    type:         opaque byte stream
    access:       read only
    mechanism:    by descriptor
    Buffer containing an object security profile. The objpro
    argument is the address of a descriptor pointing to a buffer
    that contains an encoded object security profile. The objpro
    argument eliminates the need to supply all of the component
    object protection attributes with the $CHKPRO item list. The
    objpro argument is currently reserved to Compaq.

 usrpro

    OpenVMS usage:char_string
    type:         opaque byte stream
    access:       read only
    mechanism:    by descriptor
    Buffer containing a user security profile. The usrpro argument is
    the address of a descriptor pointing to a buffer that contains an
    encoded user security profile. The usrpro argument eliminates the
    need to supply all of the component user security attributes with
    the $CHKPRO item list.

    The $CREATE_USER_PROFILE service can be used to construct a user
    security profile. When the usrpro argument is specified, any
    component user profile attributes specified in the $CHKPRO item
    list replace those contained in the user security profile.